Editing Road surface

{{About|road surface pavement material|other uses of the term "pavement"|Pavement (disambiguation)}}
{{short description|Road covered with durable surface material}}
{{Use dmy dates|date=July 2014}}
[[File:Road resurfacing.jpg|right|thumb|A road being resurfaced using a [[road roller]]]]
[[File:2004feb20 Aanleg rood fietspad.jpg|thumb|Red surfacing for a [[bicycle lane]] in the Netherlands]]
[[File:Stealth Communications laying down asphalt over fiber-optic trench in NYC.jpg|thumb|Construction crew laying down asphalt over fiber-optic trench, in New York City]]
A '''road surface''' ([[British English]]) or '''pavement''' ([[North American English]]) is the durable surface material laid down on an area intended to sustain vehicular or foot [[traffic]], such as a [[road]] or [[walkway]]. In the past, [[gravel road]] surfaces, [[macadam]], [[hoggin]], [[cobblestone]] and [[sett (paving)|granite setts]] were extensively used, but these have mostly been replaced by [[Asphalt concrete|asphalt]] or [[concrete]] laid on a compacted [[base course]]. Asphalt mixtures have been used in pavement construction since the beginning of the 20th century and are of two types: metalled (hard-surfaced) and unmetalled roads. Metalled roadways are made to sustain vehicular load and so are usually made on frequently used roads. Unmetalled roads, also known as gravel roads or dirt roads, are rough and can sustain less weight. Road surfaces are frequently [[road surface marking|marked to guide traffic]].

Today, [[permeable paving]] methods are beginning to be used for low-impact roadways and walkways to prevent flooding. Pavements are crucial to countries such as [[United States]] and [[Canada]], which heavily depend on road transportation. Therefore, research projects such as [[Long-Term Pavement Performance]] have been launched to optimize the life cycle of different road surfaces.<ref>{{cite web |first = Jean |last = Nehme |date = 14 July 2017 |url = https://highways.dot.gov/research/research-programs/infrastructure/infrastructure-overview |title = About Long-Term Pavement Performance |publisher = [[Federal Highway Administration]] |access-date = 22 October 2017}}</ref><ref>{{cite web |first = Robert |last = Raab |date = n.d. |url = http://www.trb.org/LTPPProgram/LTPPProgram.aspx |title = Long-Term Pavement Performance Studies |publisher = [[Transportation Research Board]] |access-date = 22 October 2017 }}</ref><ref>{{Cite web|url=https://nacto.org/docs/usdg/nchrp_rpt_713_thompson.pdf|title=Ford, K., Arman, M., Labi, S., Sinha, K.C., Thompson, P.D., Shirole, A.M., and Li, Z. 2012. NCHRP Report 713: Estimating life expectancies of highway assets. In Transportation Research Board, National Academy of Sciences, Washington, DC. Transportation Research Board, Washington DC.}}</ref><ref>{{Cite web|url=https://www.fhwa.dot.gov/publications/research/infrastructure/pavements/ltpp/18065/index.cfm|title=Piryonesi, S. M., & El-Diraby, T. (2018). Using Data Analytics for Cost-Effective Prediction of Road Conditions: Case of The Pavement Condition Index:[summary report] (No. FHWA-HRT-18-065). United States. Federal Highway Administration. Office of Research, Development, and Technology.|archive-url=https://web.archive.org/web/20190202153647/https://www.fhwa.dot.gov/publications/research/infrastructure/pavements/ltpp/18065/index.cfm|archive-date=2 February 2019}}</ref>

'''Pavement''', in construction, is an outdoor floor or superficial surface covering. Paving materials include [[Asphalt concrete|asphalt]], [[concrete]], stones such as [[flagstone]], [[cobblestone]], and [[Sett (paving)|setts]], [[artificial stone]], [[Brick|bricks]], [[Tile|tiles]], and sometimes wood. In [[landscape architecture]], pavements are part of the [[hardscape]] and are used on [[Sidewalk|sidewalks]], [[Road surface|road surfaces]], [[Patio|patios]], [[Courtyard|courtyards]], etc.

The term ''pavement'' comes from Latin ''{{linktext|pavimentum}}'', meaning a floor beaten or rammed down, through Old French ''pavement''.<ref>[http://triggs.djvu.org/century-dictionary.com/djvu2jpgframes.php?volno=05&page=779&query=pavement "Pavement", ''The Century Dictionary'']</ref> The meaning of a beaten-down floor was obsolete before the word entered English.<ref>"pavement, n." ''Oxford English Dictionary'' Second Edition on CD-ROM (v. 4.0) Oxford University Press, 2009</ref>

Pavement, in the form of beaten [[gravel]], dates back before the emergence of [[anatomically modern humans]]. Pavement laid in patterns like [[mosaics]] were commonly used by the Romans.<ref>"paver" def. 2. ''Oxford English Dictionary'' Second Edition on CD-ROM (v. 4.0) Oxford University Press, 2009</ref>

The [[bearing capacity]] and [[service life]] of a pavement can be raised dramatically by arranging good [[drainage]] by an open [[ditch]] or covered [[Drainage|drains]] to reduce moisture content in the pavements [[subbase]] and [[subgrade]].

==Development==
{{Main article|History of road transport}}
[[File:Carved steps along Ancient Roman Road.jpg|thumb|Old Roman road, leading from [[Jerusalem]] to [[Bayt Jibrin|Beit Gubrin]], adjacent to regional highway 375 in Israel]]
[[File:Pavement layers.png|thumb|Different layers of road including asphalt layer. The total thickness of a pavement can be measured using [[granular base equivalency]].]]
Wheeled transport created the need for better roads. Generally, natural materials cannot be both soft enough to form well-graded surfaces and strong enough to bear wheeled vehicles, especially when wet, and stay intact. In urban areas it was worthwhile to build stone-paved streets and, in fact, the first paved streets appear to have been built in [[Ur]] in 4000 BC. [[Corduroy road]]s were built in [[Glastonbury]], [[England]] in 3300 BC,<ref>Lay (1992), p51</ref> and brick-paved roads were built in the [[Indus Valley Civilisation]] on the [[Indian subcontinent]] from around the same time. Improvements in [[metallurgy]] meant that by 2000 BC stone-cutting tools were generally available in the Middle East and [[Greece]] allowing local streets to be paved.<ref>Lay (1992), p43</ref> Notably, in about 2000 BC, the [[Minoan civilization|Minoans]] built a 50&nbsp;km paved road from [[Knossos]] in northern [[Crete]] through the mountains to [[Gortyn]] and [[Leben (Crete)|Lebena]], a port on the south coast of the island, which had side drains, a 200&nbsp;mm thick pavement of [[sandstone]] blocks bound with [[clay]]-[[gypsum]] [[Mortar (masonry)|mortar]], covered by a layer of [[basalt]]ic [[flagstone]]s and had separate [[Shoulder (road)|shoulders]]. This road could be considered superior to any [[Roman roads|Roman road]].<ref>Lay (1992), p44</ref> Roman roads varied from simple corduroy roads to paved roads using deep roadbeds of tamped rubble as an underlying layer to ensure that they kept dry, as the water would flow out from between the stones and fragments of rubble, instead of becoming mud in clay soils.

Although there were attempts to rediscover Roman methods, there was little useful innovation in road building before the 18th century. The first professional road builder to emerge during the [[Industrial Revolution]] was [[John Metcalf (civil engineer)|John Metcalf]], who constructed about {{convert|180|mi|km|order=flip}} of [[toll road|turnpike road]], mainly in the north of England, from 1765, when [[Parliament of Great Britain|Parliament]] passed an act authorising the creation of [[turnpike trust]]s to build [[toll (road usage)|toll]] funded roads in the [[Knaresborough]] area.

[[Pierre-Marie-Jérôme Trésaguet]] is widely credited with establishing the first [[scientific method|scientific approach]] to road building in France at the same time as Metcalf. He wrote a memorandum on his method in 1775, which became general practice in France. It involved a layer of large rocks, covered by a layer of smaller gravel.

By the late 18th and early 19th centuries, new methods of highway construction had been pioneered by the work of two British engineers: [[Thomas Telford]] and [[John Loudon McAdam]]. Telford's method of road building involved the digging of a large trench in which a foundation of heavy rock was set. He designed his roads so that they sloped downwards from the centre, allowing drainage to take place, a major improvement on the work of Trésaguet. The surface of his roads consisted of broken stone. McAdam developed an inexpensive paving material of soil and stone aggregate (known as [[macadam]]). His road building method was simpler than Telford's, yet more effective at protecting roadways: he discovered that massive foundations of rock upon rock were unnecessary, and asserted that native soil alone would support the road and traffic upon it, as long as it was covered by a road crust that would protect the soil underneath from water and wear.<ref name=ColossusofRoads>{{citation |author=Craig, David|title=The Colossus of Roads|work=Palimpsest|publisher=Strum.co.uk|url=http://www.strum.co.uk/palimps/macadam.htm|access-date=18 June 2010}}</ref> Size of stones was central to McAdam's road building theory. The lower {{convert|200|mm|in|adj=on}} road thickness was restricted to stones no larger than {{convert|75|mm|in}}.

Modern [[tarmacadam|tarmac]] was patented by British civil engineer [[Edgar Purnell Hooley]], who noticed that spilled tar on the roadway kept the dust down and created a smooth surface.<ref name=Morton2002>{{citation |year=2002 |author=Ralph Morton|title=Construction UK: Introduction to the Industry| place=Oxford |publisher=Blackwell Science|page=51 |isbn=0-632-05852-8 |url=https://books.google.com/books?id=cW4CRawd1TgC&q=%22Edgar+Hooley%22&pg=PA51|access-date=22 June 2010}}. (Details of this story vary a bit, but the essence of is the same, as are the basic facts).</ref> He took out a patent in 1901 for tarmac.<ref name=Harrison2004>{{citation |year=2004 |author=Harrison, Ian|title=The Book of Inventions |place=Washington, DC |publisher=[[National Geographic Society]] |page=277 |isbn=978-0-7922-8296-9  |url=https://books.google.com/books?id=n4NGAAAAYAAJ&q=%22Tarmac+1902+Edgar+Purnell+Hooley+(England)+Patent+no:+GB+7796/1902+%26+US%22|access-date=23 June 2010}}</ref> Hooley's 1901 patent for tarmac involved mechanically mixing tar and aggregate prior to lay-down, and then compacting the mixture with a [[steamroller]]. The tar was modified by adding small amounts of [[Portland cement]], [[resin]], and [[pitch (resin)|pitch]].<ref>Hooley, E. Purnell, {{US patent|765975}}, "Apparatus for the preparation of tar macadam", July 26, 1904</ref>

==Asphalt==
[[File:Closeup of pavement with grass.JPG|right|thumb|Closeup of asphalt on a driveway]]
Asphalt (specifically, [[asphalt concrete]]), sometimes called flexible pavement since its viscosity causes minute deformations as it distributes loads, has been widely used since the 1920s. The viscous nature of the [[bitumen]] binder allows asphalt concrete to sustain significant [[Deformation (engineering)|plastic deformation]], although [[fatigue (material)|fatigue]] from repeated loading over time is the most common failure mechanism. Most asphalt surfaces are laid on a gravel base, which is generally at least as thick as the asphalt layer, although some 'full depth' asphalt surfaces are laid directly on the native [[subgrade]]. In areas with very soft or [[Expansive clay|expansive]] subgrades such as [[clay]] or [[peat]], thick gravel bases or stabilization of the subgrade with [[Portland cement]] or [[Lime (material)|lime]] may be required. [[Polypropylene]] and polyester [[geosynthetics]] are also used for this purpose,<ref>{{cite web|url=http://construction-on-line.com/naue_news_30_EN.pdf|publisher=NUAE|access-date=2 November 2008|date=May 2007|title=NUAE Geosynthetics Ltd. News: Project Scout Moor Wind farm|archive-url=https://web.archive.org/web/20151208101511/http://construction-on-line.com/naue_news_30_EN.pdf|archive-date=8 December 2015}}</ref> and in some northern countries a layer of [[polystyrene]] boards are used to delay and minimize frost penetration into the subgrade.<ref>{{cite web|url=http://www.geosyscorp.com/noframes/documents/BASF/BASF_800.pdf|title=Highway construction/ Ground insulation|last=Anon|date=June 1991|work=Styropor: Technical information|access-date=29 January 2010|archive-url=https://web.archive.org/web/20181002153901/http://www.geosyscorp.com/noframes/documents/BASF/BASF_800.pdf|archive-date=2 October 2018}}</ref>

Depending on the temperature at which it is applied, asphalt is categorized as hot mix, warm mix, half warm mix, or cold mix. Hot mix asphalt is applied at temperatures over {{convert|150|C|F|-1}} with a [[free floating screed]]. Warm mix asphalt is applied at temperatures of {{convert|95-120|C|F|-1}}, resulting in reduced energy usage and emissions of [[Volatile organic compound|volatile organic compounds]].<ref>{{cite web|url=https://www.fhwa.dot.gov/pavement/asphalt/wma.cfm|publisher=Federal Highway Administration|access-date=4 August 2010|date=29 October 2008|title=Warm Mix Asphalt Technologies and Research}}</ref> Cold mix asphalt is often used on lower-volume rural roads, where hot mix asphalt would cool too much on the long trip from the [[asphalt plant]] to the construction site.<ref>{{cite web|url=http://www.clrp.cornell.edu/TrainingEvents/PDF-2009/W0835_Blades.pdf|archive-url=https://web.archive.org/web/20121021103011/http://www.clrp.cornell.edu/TrainingEvents/PDF-2009/W0835_Blades.pdf|archive-date=2012-10-21|publisher=Cornell Local Roads Program|access-date=4 August 2010|date=June 2009|title=Hot, Warm, Luke Warm and Cold Mix Asphalt}}</ref>

An asphalt concrete surface will generally be constructed for high-volume primary highways having an average annual daily traffic load greater than 1,200 vehicles per day.<ref name="cold" /> Advantages of asphalt roadways include relatively low noise, relatively low cost compared with other paving methods, and perceived ease of repair. Disadvantages include less durability than other paving methods, less tensile strength than concrete, the tendency to become slick and soft in hot weather, and a certain amount of [[hydrocarbon]] pollution to soil and [[groundwater]] or [[waterway]]s.[[File:Road resurfacing (2).jpg|thumb|Laying asphalt]]In the mid-1960s, [[rubberized asphalt]] was used for the first time, mixing crumb rubber from used tires with asphalt.<ref>{{cite book|url=https://books.google.com/books?id=annMBQAAQBAJ&pg=PA195|author1=David Jones|author2=John Harvey|author3=Imad L. Al-Qadi|author4=Angel Mateos|year=2012|publisher=CRC Press|title=Advances in Pavement Design through Full-scale Accelerated Pavement Testing|isbn=978-0-203-07301-8}}</ref> While a potential use for tires that would otherwise fill landfills and present a fire hazard, rubberized asphalt has shown greater incidence of wear in freeze-thaw cycles in temperate zones because of the non-homogeneous expansion and contraction with non-rubber components. The application of rubberized asphalt is more temperature-sensitive and in many locations can only be applied at certain times of the year.<ref name="jordanssurfacing.co.uk">{{Cite web  | title = What is Rubberised Asphalt Commonly Used For | date = 12 February 2021 | url = https://jordanssurfacing.co.uk/what-is-rubberised-asphalt-commonly-used-for/ | access-date = 12 February 2021 }}</ref> Study results of the long-term acoustic benefits of rubberized asphalt are inconclusive. Initial application of rubberized asphalt may provide a reduction of 3–5 decibels (dB) in tire-pavement-source noise emissions; however, this translates to only 1–3 dB in total traffic-noise reduction when combined with the other components of traffic noise. Compared to traditional passive attenuating measures (e.g., noise walls and earth berms), rubberized asphalt provides shorter-lasting and lesser acoustic benefits at typically much greater expense.{{citation needed|date=February 2024}}

==Concrete==
{{Further|Concrete}}
[[File:CASR85 SanJose.jpg|thumbnail|Concrete roadway in [[San Jose, CA|San Jose]], [[California]]]]
[[File:2014-08-29 15 31 39 View southeast along Stuyvesant Avenue in Ewing, New Jersey, with concrete pavement likely dating to the 1950s.JPG|thumb|left|A concrete road in [[Ewing Township, New Jersey|Ewing]], [[New Jersey]]]]
Concrete surfaces (specifically, [[Portland cement]] concrete) are created using a concrete mix of Portland cement, [[Construction aggregate|coarse aggregate]], [[sand]], and water. In virtually all modern mixes there will also be various admixtures added to increase workability, reduce the required amount of water, mitigate harmful chemical reactions, and for other beneficial purposes. In many cases there will also be Portland cement substitutes added, such as [[fly ash]]. This can reduce the cost of the concrete and improve its physical properties. The material is applied in a freshly mixed slurry and worked mechanically to compact the interior and force some of the cement slurry to the surface to produce a smoother, denser surface free from honeycombing. The water allows the mix to combine molecularly in a chemical reaction called [[Mineral hydration|hydration]].

Concrete surfaces have been classified into three common types: jointed plain (JPCP), jointed reinforced (JRCP) and continuously reinforced (CRCP). The one item that distinguishes each type is the jointing system used to control crack development.

One of the major advantages of concrete pavements is they are typically stronger and more durable than asphalt roadways. The surface can be grooved to provide a durable skid-resistant surface. Concrete roads are more economical to drive in terms of fuel consumption, they reflect light better, and they last significantly longer than other paving surfaces; but they have a much smaller market share than other paving solutions.<ref>{{Cite web |date=2014-12-05 |title=LCA Research Brief: Mapping of Excess Fuel Consumption |url=https://cshub.mit.edu/news/lca-research-brief-mapping-excess-fuel-consumption |access-date=2022-06-07 |website=cshub.mit.edu}}</ref> Modern paving methods and design methods have changed the economics of concrete paving so that a well-designed and placed concrete pavement will be cheaper in initial cost and significantly cheaper over the life cycle.<ref>{{Cite web |date=2022-01-11 |title=Concrete Roads |url=https://www.concreteformworksydney.com/concrete-roads/ |access-date=2022-06-27 |website=concreteformworksydney.com}}</ref> Another important advantage is that waterproof concrete can be used, which eliminates the need to place storm drains next to the road and reduces the need for a slightly sloped driveway to drain rainwater. Avoiding rainwater discharge by using runoff also means less electricity is needed (otherwise more pumps would be needed in the water distribution system) and rainwater is not polluted because it no longer mixes with polluted water. Rather, it is immediately absorbed by the earth.<ref>{{Cite web |date=2003-03-29 |title=Road Infrastructure Strategic Framework for South Africa A Discussion Document |url=http://www.transport.gov.za/library/docs/rifsa/infor.html |access-date=2022-06-27 |website=transport.gov.za|archive-url=https://web.archive.org/web/20070927063243/http://www.transport.gov.za/library/docs/rifsa/infor.html |archive-date=27 September 2007 }}</ref> A previous disadvantage was that they had a higher initial cost and could be more time-consuming to construct. This cost can typically be offset through the long life cycle of the pavement and the higher cost of bitumen. Concrete pavement can be maintained over time utilizing a series of methods known as [[Concrete Pavement Restoration|concrete pavement restoration]] which include [[Diamond grinding of pavement|diamond grinding]], [[dowel bar retrofit]]s, joint and crack sealing, cross-stitching, etc. Diamond grinding is also useful in reducing noise and restoring skid resistance in older concrete pavement.<ref>{{cite web|title=Concrete Pavement Restoration |url=http://www.pavement.com/CPP/2004/December04.pdf |access-date=7 April 2012|archive-url=https://web.archive.org/web/20120417114823/http://www.pavement.com/CPP/2004/December04.pdf |archive-date=17 April 2012|df=dmy-all}}</ref><ref>{{cite web|title=Concrete Pavement Rehabilitation Guide for Diamond Grinding |url=https://www.fhwa.dot.gov/pavement/pub_details.cfm?id=168 |access-date=7 April 2012}}</ref>

The first street in the United States to be paved with concrete was [[Court Avenue]] in [[Bellefontaine, Ohio]] in 1893.<ref>{{cite web | url=http://www.cityprofile.com/ohio/photos/4358-bellefontaine-court_avenue2.html | title=Bellefontaine, Ohio: Court Avenue photo | publisher=City Profile | date=17 February 2011 | access-date=2 April 2018 }}</ref><ref>{{cite journal | last1 = Lee | first1 = B. J. | last2 = Lee | first2 = H. | year = 2004 | title = Position-Invariant Neural Network for Digital Pavement Crack Analysis | journal = Computer-Aided Civil and Infrastructure Engineering | volume = 19 | issue = 2| pages = 105–118 | doi = 10.1111/j.1467-8667.2004.00341.x | s2cid = 109522695 }}</ref> The first mile of concrete pavement in the United States was on [[M-1 (Michigan highway)|Woodward Avenue]] in [[Detroit|Detroit, Michigan]] in 1909.<ref>{{cite book |last1=Kulsea |first1=Bill |last2=Shawver |first2= Tom |title=Making Michigan Move: A History of Michigan Highways and the Michigan Department of Transportation |url =  https://en.wikisource.org/wiki/Making_Michigan_Move#4 |year=1980 |publisher=Michigan Department of Transportation |location=Lansing, Michigan |oclc=8169232 |page= 4 |access-date = January 18, 2021 |via = [[Wikisource]] }}</ref> Following these pioneering uses, the [[Lincoln Highway#Concept and promotion|Lincoln Highway Association]], established in October 1913 to oversee the creation of one of the United States' earliest east-west transcontinental highways for the automobile, began to establish [[Lincoln Highway#Seedling miles and the ideal section|"seedling miles"]] of specifically concrete-paved roadbed in various places in the [[Midwestern United States|American Midwest]], starting in 1914 west of [[Malta, Illinois]], while using concrete with the specified concrete "ideal section" for the Lincoln Highway in [[Lake County, Indiana]], during 1922 and 1923.<ref>{{cite web |url=https://highways.dot.gov/highway-history/general-highway-history/lincoln-highway |title=The Lincoln Highway |last=Weingroff |first=Richard F. |date=7 April 2011 |website=[[Federal Highway Administration|Federal Highway Administration (FHWA)]] |publisher=Federal Highway Administration |access-date=25 September 2017 |quote=The LHA also sponsored short concrete "Seedling Mile" object lesson roads in many locations (the first, built in the fall of 1914, was just west of Malta, Illinois). The "Seedling Miles," according to the LHA's 1924 guide, were intended "to demonstrate the desirability of this permanent type of road construction" and "crystallize public sentiment" for "further construction of the same character." Generally, the LHA worked with the Portland Cement Association to arrange donations of cement for the seeding mileage...The most famous "seedling" and one of the most talked about portions of the Lincoln Highway was the 1.3-mile "Ideal Section" between Dyer and Schererville in Lake County, Indiana. In 1920, the LHA decided to develop a model section of road that would be adequate not only for current traffic but for highway transportation over the following 2 decades. The LHA assembled 17 of the country's foremost highway experts for meetings in December 1920 and February 1921 to decide design details of the Ideal Section. They agreed on such features as: A 110-foot right-of-way; A 40-foot wide concrete pavement 10 inches thick (maximum loads of 8,000 pounds per wheel were the basis for the pavement design);     Minimum radius for curves of 1,000 feet, with guardrail at all embankments;     Curves superelevated (i.e., banked) for a speed of 35 miles per hour;     No grade crossings or advertising signs; and     A footpath for pedestrians.}}</ref>

Concrete roadways may produce more noise than asphalt from tire noise on cracks and expansion joints. A concrete pavement composed of multiple slabs of uniform size will produce a periodic sound and vibration in each vehicle as its tires pass over each expansion joint. These monotonous repeated sounds and vibrations can cause a [[Highway hypnosis|fatiguing or hypnotic effect]] upon the driver over the course of a long journey.

==Composite pavement==
[[File:Composite pavement x-sect.jpg|thumb|An example of composite pavement: hot-mix asphalt overlaid onto Portland cement concrete pavement]]
Composite pavements combine a Portland cement concrete sublayer with an asphalt overlay. They are usually used to rehabilitate existing roadways rather than in new construction. Asphalt overlays are sometimes laid over distressed concrete to restore a smooth wearing surface.<ref>{{cite book |title=Guidelines for the Rehabilitation of Concrete Pavements Using Asphalt Overlays (FHWA TPF-5(149) Final Report) |year=2012 |last1=Khazanovich |first1=L. |last2=Lederle |first2=R. |last3=Tompkins |first3=D. |last4=Harvey |first4=J.T. |last5=Signore |first5=J. }}</ref> A disadvantage of this method is that movement in the joints between the underlying concrete slabs, whether from thermal expansion and contraction, or from deflection of the concrete slabs from truck [[axle load]]s, usually causes ''[[reflective crack]]s'' in the asphalt. 

To decrease reflective cracking, concrete pavement is broken apart through a ''break and seat,'' ''crack and seat'', or ''[[rubblization]]'' process. Geosynthetics can be used for reflective crack control.<ref>{{cite journal|last1=Moghadas Nejad |first1=Fereidoon|last2=Noory |first2=Alireza |last3=Toolabi|first3=Saeed|last4=Fallah|first4=Shahab |title=Effect of using geosynthetics on reflective crack prevention |journal=International Journal of Pavement Engineering|date=8 August 2014 |volume=16|issue=6|pages=477–487|doi=10.1080/10298436.2014.943128|s2cid=137582766}}</ref> With break and seat and crack and seat processes, a heavy weight is dropped on the concrete to induce cracking, then a heavy roller is used to seat the resultant pieces into the subbase. The main difference between the two processes is the equipment used to break the concrete pavement and the size of the resulting pieces. The theory is that frequent small cracks will spread thermal stress over a wider area than infrequent large joints, reducing the stress on the overlying asphalt pavement. "Rubblization" is a more complete fracturing of the old, worn-out concrete, effectively converting the old pavement into an aggregate base for a new asphalt road.<ref>{{cite book|last1=Lavin|first1=Patrick|title=Asphalt Pavements: A Practical Guide to Design, Production and Maintenance for Engineers and Architects|date=2003|publisher=CRC Press|isbn=978-0-203-45329-2}}</ref>

The [[whitetopping]] process uses Portland cement concrete to resurface a distressed asphalt road.

==Recycling==
[[File:AsphaltMillingMachineSEBoise.webm|thumb|An asphalt milling machine in [[Boise, Idaho]]]]
Distressed pavement can be reused when rehabilitating a roadway. The existing pavement is broken up and may be ground on-site through a process called [[Pavement milling|milling]]. This pavement is commonly referred to as reclaimed asphalt pavement (RAP). RAP can be transported to an asphalt plant, where it will be stockpiled for use in new pavement mixes,<ref name=":0">{{Cite journal|last1=Karlsson|first1=Robert|last2=Isacsson|first2=Ulf|date=2006-02-01|title=Material-Related Aspects of Asphalt Recycling—State-of-the-Art|url=https://ascelibrary.org/doi/pdf/10.1061/(ASCE)0899-1561(2006)18:1(81)|journal=Journal of Materials in Civil Engineering|language=EN|volume=18|issue=1|pages=81–92|doi=10.1061/(asce)0899-1561(2006)18:1(81)|issn=0899-1561|url-access=subscription}}</ref> or it may be recycled in-place using the techniques described below. 

===In-place recycling methods===
*'''Rubblizing of pavement:''' Existing concrete pavement is milled into gravel-sized particles. Any steel reinforcing is removed, and the ground pavement is compacted to form the base and/or sub-base layers for new asphalt pavement.<ref>{{Cite journal |last=Heckel|first=L. B.|date=2002-04-01|title=Rubblizing with Bituminous Concrete Overlay - 10 Years' Experience in Illinois |website=The National Academies of Sciences, Engineering, and Medicine |url=https://trid.trb.org/view/707428}}</ref> Ground pavement may also be compacted for use on [[gravel road]]s.<ref name=":0" /> &nbsp;
*'''Cold in-place recycling:''' Bituminous pavement is ground or milled into small particles. The asphalt millings are blended with asphalt emulsion, foamed bitumen, or soft bitumen to rejuvenate the aged asphalt binder.<ref name=":0" /><ref>{{Cite CiteSeerX |last1=Al-Qadi|first1=Imad|last2=Elseifi|first2=Mostafa|last3=Carpenter|first3=Samuel|date=2007-03-01|title=Reclaimed Asphalt Pavement - A Literature Review |citeseerx=10.1.1.390.3460}}</ref> New aggregate may also be added. The resulting asphalt mix is paved and compacted. It may serve as the top pavement layer, or it may be overlaid with new asphalt after curing.<ref name="ReferenceA">{{Cite web|url=https://cornell.app.box.com/v/clrp-ws-app|title=Asphalt Paving Principles|date=March 2004|website=www.clrp.cornell.edu|publisher=Cornell Local Roads Program|access-date=2016-10-05}}</ref>
*'''Hot in-place recycling:''' Bituminous pavement is heated to {{convert|120-150|C|F|-1}}, milled, combined with a rejuvenating agent and/or virgin asphalt binder, and compacted. It may then be overlaid with new asphalt concrete.<ref name="ReferenceA" /> This process typically recycles the top {{convert|50|mm|in|0|abbr=on}} or less and may be used to correct surface defects, such as rutting or polishing.<ref name="ReferenceA" /> To preserve the condition of the asphalt binder and avoid excessive hydrocarbon emissions, heating is typically achieved gradually through the use of infrared or hot air heaters.<ref name=":0" />
*'''[[Full depth recycling|Full depth reclamation]]:''' The full thickness of the asphalt pavement and underlying material is pulverized to provide a uniform blend of material.<ref name=":0" /><ref name="ReferenceA" /> A binding agent or stabilizing material may be mixed in to form a base course for the new pavement, or it may be left unbound to form a sub-base course. Common binding agents include asphalt emulsion, fly ash, hydrated lime, Portland cement, and calcium chloride.<ref name=":0" /><ref name="ReferenceA" /> Virgin aggregate, RAP, or crushed Portland cement may also be added to improve the [[Soil gradation|gradation]] and mechanical properties of the mix.<ref name="ReferenceA" /> This technique is typically used to address structural failures in the pavement, such as alligator cracking, deep rutting, and shoulder drop-off.<ref name="ReferenceA" />

==Bituminous surface==
{{main article|Chipseal}}
[[File:Gravel road with no dust.webp|thumb|Newly installed chip seal surface on Ellsworth Road in [[Tomah, Wisconsin]]]]
'''Bituminous surface treatment''' (BST) or '''chipseal''' is used mainly on low-traffic roads, but also as a sealing coat to rejuvenate an asphalt concrete pavement. It generally consists of aggregate spread over a sprayed-on asphalt [[emulsion]] or cut-back asphalt cement. The aggregate is then embedded into the asphalt by rolling it, typically with a rubber-tired [[road roller|roller]]. This type of surface is described by a wide variety of regional terms including "chip seal", "tar and chip", "oil and stone", "seal coat", "sprayed seal",<ref>[http://www.lgam.info/sprayed-seal Sprayed Seal], Local Government & Municipal Knowledge Base, accessed 29 January 2010</ref> "surface dressing",<ref>{{cite book|last1=Gransberg|first1=Douglas D.|first2= David M. B.|last2=James|others=National Cooperative Highway|title=Chip Seal Best Practices|url=https://books.google.com/books?id=gTCHtuGENwQC|year=2005|publisher=Transportation Research Board|isbn=978-0-309-09744-4|pages=13–20}}
</ref> "microsurfacing",<ref>{{Cite web|url=https://dpw.lacounty.gov/gmed/lacroads/TreatmentMicrosurfacing.aspx|title = Microsurfacing Treatment Types}}</ref> "seal",<ref>{{Cite web|url=https://www.nzherald.co.nz/nz/more-than-100-motorists-lodge-damage-claims-after-road-seal-peels-off-at-dome-valley/X755QMIUAJBZNJX4C4PDXFX3SE/|title = More than 100 motorists lodge damage claims after road seal peels off at Dome Valley}}</ref> or simply as "bitumen".

BST is used on hundreds of miles of the [[Alaska Highway]] and other similar roadways in [[Alaska]], the [[Yukon Territory]], and northern [[British Columbia]]. The ease of application of BST is one reason for its popularity, but another is its flexibility, which is important when roadways are laid down over unstable terrain that thaws and softens in the spring.

Other types of BSTs include micropaving, slurry seals and Novachip. These are laid down using specialized and proprietary equipment. They are most often used in urban areas where the roughness and loose stone associated with chip seals is considered undesirable.

===Thin membrane surface===
A thin membrane surface (TMS) is an [[oil]]-treated [[Construction aggregate|aggregate]] which is laid down upon a [[gravel road]] bed, producing a dust-free road.<ref>{{cite web|last=Lazic |first=Zvjezdan |author2=Ron Gerbrandt |title=Feasibility of Alternative salt storage structures in Saskatchewan Neilburg case study |work=Measuring performance indicators for decision-making in winter maintenance operations. 2004 Annual conference of the Transportation Association of Canada |publisher=Saskatchewan Highways and Transportation |year=2004 |url=http://www.tac-atc.ca/English/pdf/conf2004/lazic2.pdf |access-date=25 February 2009 |archive-url=https://web.archive.org/web/20090318012448/http://www.tac-atc.ca/English/pdf/conf2004/lazic2.pdf |archive-date=18 March 2009 }}
</ref> A TMS road reduces mud problems and provides stone-free roads for local residents where loaded truck traffic is negligible. The TMS layer adds no significant structural strength, and so is used on secondary highways with low traffic volume and minimal weight loading. Construction involves minimal subgrade preparation, following by covering with a {{convert|50|to(-)|100|mm|in|0|adj=on}} cold mix [[Bitumen|asphalt]] aggregate.<ref name="cold">{{cite web
|last=Gerbrandt
|first=Ron
|author2=Tim Makahoniuk |author3=Cathy Lynn Borbely |author4=Curtis Berthelot
  | title = Guidelines must be followed strictly – No exceptions
 | work = Effect of Cold-in-place recycling on the Heavyweight Trucking Industry
 | publisher =6th International Conference on Heavy Vehicle Weights and Dimension Proceedings
 | year = 2000
 | url =http://engrwww.usask.ca/entropy/tc/publications/pdf/cirheavyweighttruckingpostedfinalpdf.pdf
 | access-date =25 January 2009 }}
</ref> The Operation Division of the [[Ministry of Highways and Infrastructure (Saskatchewan)|Ministry of Highways and Infrastructure]] in [[Saskatchewan]] has the responsibility of maintaining {{convert|6102|km|mi}} of thin membrane surface (TMS) highways.<ref name="MHI">{{cite web  | title = Highways and Infrastructure&nbsp;— Government of Saskatchewan | url = http://www.highways.gov.sk.ca/department-overview/ | access-date =15 April 2008 |archive-url = https://web.archive.org/web/20080208211924/http://www.highways.gov.sk.ca/department-overview/ <!-- Bot retrieved archive --> |archive-date = 8 February 2008}}</ref>

===Otta seal===
[[Otta seal]] is a low-cost road surface using a {{convert|16|–|30|mm|in|frac=8|adj=mid|-thick}}  mixture of [[bitumen]] and crushed rock.<ref name="otta">{{cite news |url=http://www.odt.co.nz/the-regions/central-otago/45404/new-dust-suppression-method |title=New dust suppression method |author=Manins, Rosie |date=28 February 2009 |work=[[Otago Daily Times]] |access-date=5 November 2011}}</ref>

== Gravel surface <span class="anchor" id="Metalling"></span><!-- [[Road metal]], [[Road metals]], & [[Metalled]] link here. -->==
{{Main article|Gravel road}}
[[File:Gravel road, Namibia.jpg|thumb|[[Gravel road]] in [[Namibia]]]]
[[Gravel]] is known to have been used extensively in the construction of roads by soldiers of the [[Roman Empire]] (see [[Roman road]]) but in 1998 a limestone-surfaced road, thought to date back to the [[Bronze Age]], was found at [[Yarnton]] in Oxfordshire, Britain.<ref>{{cite journal |last=Anon |date=July 1998 |title=Bronze Age metalled road near Oxford |journal=British Archaeology: News |issue=36 |url=http://www.britarch.ac.uk/ba/ba36/ba36news.html |access-date=29 January 2010}}</ref> Applying gravel, or "'''metalling'''", has had two distinct usages in road surfacing. The term '''road metal''' refers to the broken [[Rock (geology)|stone]] or [[Scoria|cinder]]s used in the [[Road#Construction|construction or repair of roads]] or [[Rail track|railway]]s,<ref>{{cite web |url=http://www.merriam-webster.com/netdict/road%20metal |title=Road metal |last=Anon |work=Merriam-Webster online dictionary |publisher=Merriam Webster inc. |access-date=29 January 2010}}</ref> and is derived from the [[Latin]] ''metallum'', which means both "[[Mining|mine]]" and "[[quarry]]".<ref>{{cite web |url=http://dictionary.reference.com/browse/metal |title=Metal |last=Anon |work=Online etymological dictionary |publisher=2001 Douglas Harper |access-date=29 January 2010}}</ref> The term originally referred to the process of creating a gravel roadway. The route of the roadway would first be dug down several feet and, depending on local conditions, [[French drain]]s may or may not have been added. Next, large stones were placed and compacted, followed by successive layers of smaller stones, until the road surface was composed of small stones compacted into a hard, durable surface. "Road metal" later became the name of [[Rock (geology)|stone]] chippings mixed with [[tar]] to form the road-surfacing material [[Tarmacadam|tarmac]]. A road of such material is called a "'''metalled road'''" in Britain, a "'''paved road'''" in Canada and the US, or a "'''sealed road'''" in parts of Canada, Australia and New Zealand.<ref>{{cite web |url=http://www.wordwebonline.com/en/METALLEDROAD |title=Metalled Road |last=Anon |work=World Web Online |publisher=WordWeb Software |access-date=29 January 2010}}</ref>

A granular surface can be used with a traffic volume where the annual average daily traffic is 1,200 vehicles per day or less.{{Citation needed|date=March 2009}} There is some structural strength if the road surface combines a sub base and base and is topped with a double-graded seal aggregate with emulsion.<ref name="cold"/><ref name="aggregate">{{cite web |title=Surfacing Aggregate |work=Product brochure |publisher=Afrisam.com South Africa |year=2008 |url=http://www.afrisam.co.za/WCM/Internet/Internet.nsf/LookupAllDocsByUNID/4149A26FE5A72F0165257448001ECAFB/$File/Surfacing%20aggregate%20lr.pdf |access-date=25 January 2009 |archive-url=https://web.archive.org/web/20090318012449/http://www.afrisam.co.za/WCM/Internet/Internet.nsf/LookupAllDocsByUNID/4149A26FE5A72F0165257448001ECAFB/$File/Surfacing%20aggregate%20lr.pdf |archive-date=18 March 2009 }}
</ref> Besides the {{convert|4929|km|mi}} of granular pavements maintained in Saskatchewan, around 40% of [[New Zealand]] roads are unbound granular pavement structures.<ref name="MHI"/><ref>{{cite web |last= Oeser |first= Markus |author2 = Sabine Werkmeister |author3 = Alvaro Gonzales |author4 = David Alabaster |title = Experimental and numerical simulation of loading impact on modified granular pavements |work= 8th World Congress on Computational Mechanics 5th European Congress on computational methods in applied sciences and engineering ECCOMAS |publisher = 6th International Conference on Heavy Vehicle Weights and Dimension Proceedings |year = 2008 |url = http://www.iacm-eccomascongress2008.org/cd/offline/pdfs/a1841.pdf |access-date = 25 January 2009 |archive-url = https://web.archive.org/web/20090318012448/http://www.iacm-eccomascongress2008.org/cd/offline/pdfs/a1841.pdf |archive-date = 18 March 2009 |df = dmy-all}}</ref>

The decision whether to pave a gravel road or not often hinges on traffic volume. It has been found that maintenance costs for gravel roads often exceed the maintenance costs for paved or surface-treated roads when traffic volumes exceed 200 vehicles per day.<ref>{{Cite web |url=http://www.ctre.iastate.edu/pubs/midcon2003/RukashazaTreatments.pdf |title=Cost Comparison of Treatments Used to Maintain or Upgrade Aggregate Roads |author=Mary C. Rukashaza-Mukome|work=Proceedings of the 2003 Mid-Continent Transportation Research Symposium |publisher=Iowa State University |year=2003 |access-date=16 September 2011 |display-authors=etal}}</ref>
[[File:Gravel road ahead - Road 60 Iceland.JPG|thumb|Pavement ends and turns into gravel surface road.]]
Some communities are finding it makes sense to convert their low-volume paved roads to aggregate surfaces.<ref>{{Cite news |url=https://www.wsj.com/articles/SB10001424052748704913304575370950363737746 |title=Roads to Ruin: Towns Rip Up the Pavement |journal=Wall Street Journal |date=17 July 2010 |access-date=16 September 2011 }}</ref>

==Other surfaces==
'''Pavers''' (or '''paviours'''), generally in the form of pre-cast concrete blocks, are often used for aesthetic purposes, or sometimes at [[harbor|port]] facilities that see long-duration pavement loading. [[Block paving|Pavers]] are rarely used in areas that see high-speed vehicle traffic.[[File:Brick paving machine.jpg|thumb|Brick paving machine]]

[[Brick]], [[cobblestone]], [[Sett (paving)|sett]], [[Plank road|wood plank]], and wood block pavements such as [[Nicolson pavement]], were once common in [[urban area]]s throughout the world, but fell out of fashion in most countries, due to the high cost of labor required to lay and maintain them, and are typically only kept for historical or aesthetic reasons.{{Citation needed|date=May 2010}} In some countries, however, they are still common in local streets. In the [[Netherlands]], brick paving has made something of a comeback since the adoption of a major nationwide [[traffic safety]] program in 1997. From 1998 through 2007, more than 41,000&nbsp;km of city streets were converted to local access roads with a speed limit of 30&nbsp;km/h, for the purpose of [[traffic calming]].<ref>{{cite book |author=<!--Staff writer(s); no by-line.--> |date=2009 |title=De balans opgemaakt: Duurzaam Veilig 1998–2007 |language=nl |trans-title=Sustainable Safety in the Netherlands - 1998–2007 |url=http://www.swov.nl/rapport/Balans_10_jaar_DV.pdf |publisher=[[SWOV – Dutch Institute for Road Safety Research]] |page=6 (English abstract) |isbn=978-90-73946-06-4 |access-date=13 July 2014}}</ref> One popular measure is to use brick paving - the noise and vibration slows motorists down. At the same time, it is not uncommon for cycle paths alongside a road to have a smoother surface than the road itself.<ref>{{cite web |url=http://www.aviewfromthecyclepath.com/2011/04/road-noise-cobbles-and-smooth-asphalt.html |title=Road noise, cobbles and smooth asphalt |last=Hembrow |first=David |date=25 April 2011 |website=A view from the cycle path |access-date=14 August 2014}}</ref><ref>{{cite AV media |people=Fred Young |date=23 February 2013 |title=What can Seattle learn from Dutch street design? |medium=presentation video |url=https://www.youtube.com/watch?v=l0GA901oGe4 | archive-url=https://ghostarchive.org/varchive/youtube/20211113/l0GA901oGe4| archive-date=2021-11-13 | url-status=live|access-date=14 August 2014 |time=3:49 and 9:19 min. |publisher=Seattle Neighborhood Greenways |quote=... the cycle track is asphalt (...) and the lane for cars is brick ... }}{{cbignore}}</ref>

Although rarely constructed today, early-style [[macadam]] and [[Tarmacadam|tarmac]] pavements are sometimes found beneath modern asphalt concrete or Portland cement concrete pavements, because the cost of their removal at the time of renovation would not significantly benefit the durabilty and longevity of the newer surface.

There are ways to create the appearance of brick pavement, without the expense of actual bricks. The first method to create brick texture is to heat an asphalt pavement and use metal wires to imprint a brick pattern using a [[compactor]] to create [[stamped asphalt]]. A similar method is to use rubber imprinting tools to press over a thin layer of cement to create [[decorative concrete]]. Another method is to use a brick pattern stencil and apply a surfacing material over the stencil. Materials that can be applied to give the color of the brick and skid resistance can be in many forms. An example is to use colored [[polymer concrete|polymer-modified concrete slurry]] which can be applied by [[screed]]ing or spraying.<ref>{{cite web|title=Endurablend Systems for Color Surfacing - Colors, Seals, Textures and Protects to Extend Service Life of Asphalt and Concrete Pavement Surfaces|url=http://www.pavementsurfacecoatings.com/wp-content/uploads/2013/12/EB_FLY_COLOR_4.11.pdf|access-date=13 November 2014}}</ref> Another material is [[Construction aggregate|aggregate]]-reinforced [[thermoplastic]] which can be heat applied to the top layer of the brick-pattern surface.<ref>{{cite book|title=High-Performance Crosswalks|publisher=Alternative Paving Concepts|url=http://www.alternative-paving.com/downloads/StreetPrint_XD.pdf|access-date=13 November 2014}}</ref> Other coating materials over stamped asphalt are paints and two-part [[epoxy]] coating.<ref>{{cite web|title=Decorative Stamped Asphalt|url=http://www.thermotrack.net/stampedasphalt.html|publisher=ThermOTrack|access-date=13 November 2014}}</ref>

<gallery class="center" widths="200" heights="150">
File:Brick sidewalk in Chicago.JPG|Concrete pavers
File:Paving in Haikou 02.jpg|Replacing the old road with concrete blocks in Bo'ao Road area, [[Haikou]] City, [[Hainan]], [[China]]
File:Construction of a crosswalk using polymer modified cement slurry.jpg|Polymer cement overlaying to change asphalt pavement to brick texture and color to create decorative crosswalk
</gallery>

==Acoustical implications==
Roadway surfacing choices are known to affect the intensity and spectrum of sound emanating from the tire/surface interaction.<ref>{{cite journal |last1=Hogan |first1=C. Michael |title=Analysis of highway noise |journal=Water, Air, and Soil Pollution |date=September 1973 |volume=2 |issue=3 |pages=387–392 |doi=10.1007/BF00159677 |bibcode=1973WASP....2..387H |s2cid=109914430 }}</ref> Initial applications of noise studies occurred in the early 1970s. Noise phenomena are highly influenced by vehicle speed.

Roadway surface types contribute differential noise effects of up to 4 [[decibel|dB]], with chip seal type and grooved roads being the loudest, and [[#Concrete|concrete surface]]s without spacers being the quietest. [[Asphalt concrete|Asphalt]]ic surfaces perform intermediately relative to concrete and [[chip seal]]. [[Rubberized asphalt]] has been shown to give a 3–5&nbsp;dB reduction in tire-pavement noise emissions, and a marginally discernible 1–3&nbsp;dB reduction in total road noise emissions when compared to conventional asphalt applications.

<gallery class="center" mode="packed">
File:Small cobbles.jpg|Cobbles
File:Rambla waves IMG 2089.JPG|Decorative wavy pattern on [[La Rambla, Barcelona|La Rambla]]
File:Wallpaper group-pgg-2.jpg|Decorative mock-brick pattern
File:Wallpaper group-p3-1.jpg|Decorative pentagonal brickwork pattern
</gallery>

==Surface deterioration==
{{See also|Pothole|Crocodile cracking|Rut (roads)|Bleeding (roads)|Pavement performance modeling}}
[[File:002 Damaged road surface background - cracked asphalt blacktop in Spain.jpg|upright|thumb|Cracked asphalt surface]]
[[File:Asphalt deterioration.jpg|upright|thumb|Deteriorating [[Asphalt concrete|asphalt]]]]
[[File:Portlandroadrut.jpg|thumb|A patched road rut at a [[Portland, Oregon|Portland]] [[Oregon]] bus stop. During the summer this part of the road will be hot and combined with a bus’s high [[ground pressure]] will compress and deform part of the road. Due to the lower elevation from the driveway, a large portion of the buses weight leans on one wheel causing damage to the road. Despite the repairs, you can see the patch is already damaged. This is all happens yearly.]]
As pavement systems primarily fail due to [[fatigue (material)|fatigue]] (in a manner similar to [[metal]]s), the damage done to pavement increases with the fourth power of the [[axle load]] of the vehicles traveling on it. According to the [[AASHO Road Test]], heavily loaded [[truck]]s can do more than 10,000 times the damage done by a normal passenger car. [[Tax]] rates for trucks are higher than those for cars in most countries for this reason, though they are not levied in proportion to the damage done.<ref>[http://epw.senate.gov/107th/Dull_093002.htm Statement Of Garth Dull For The Senate Epw Committee<!-- Bot generated title -->]</ref> Passenger cars are considered to have little practical effect on a pavement's service life, from a materials fatigue perspective.

Other failure modes include aging and surface abrasion. As years go by, the binder in a bituminous [[wearing course]] gets stiffer and less flexible. When it gets "old" enough, the surface will start losing aggregates, and [[macrotexture]] depth increases dramatically. If no maintenance action is done quickly on the wearing course, [[pothole]]s will form. The [[freeze-thaw]] cycle in cold climates will dramatically accelerate pavement deterioration, once water can penetrate the surface. Clay and fumed silica [[nanoparticle]]s may potentially be used as efficient UV-anti aging coatings in asphalt pavements.

If the road is still structurally sound, a bituminous surface treatment, such as a [[chipseal]] or surface dressing can prolong the life of the road at low cost. In areas with cold climate, [[studded tire]]s may be allowed on passenger cars. In Sweden and Finland, studded passenger car tires account for a very large share of pavement [[Rut (roads)|rutting]].<ref>{{Cite web|url=https://mnlandclearing.com/minnesota-land-clearing-services/|title=Land Clearing|date=2019-01-11|website=MN Land Clearing|language=en-US|access-date=2019-10-10}}</ref>

The physical properties of a stretch of pavement can be tested using a [[falling weight deflectometer]].

Several design methods have been developed to determine the thickness and composition of road surfaces required to carry predicted traffic loads for a given period of time. Pavement design methods are continuously evolving. Among these are the [[Shell Pavement design]] method, and the [[American Association of State Highway and Transportation Officials]] (AASHTO) 1993/98 "Guide for Design of Pavement Structures". A mechanistic-empirical design guide was developed through the NCHRP process, resulting in the Mechanistic Empirical Pavement Design Guide (MEPDG), which was adopted by AASHTO in 2008, although MEPDG implementation by state departments of transportation has been slow.<ref name="Li Xiao Wang Hall 2011 pp. 114–133">{{cite journal |last1=Li |first1=Qiang |last2=Xiao |first2=Danny X. |last3=Wang |first3=Kelvin C. P. |last4=Hall |first4=Kevin D. |last5=Qiu |first5=Yanjun |title=Mechanistic-empirical pavement design guide (MEPDG): a bird's-eye view |journal=Journal of Modern Transportation |date=27 September 2013 |volume=19 |issue=2 |pages=114–133 |doi=10.1007/bf03325749 |doi-access=free }}</ref>

Further research by [[University College London]] into pavements has led to the development of an indoor, 80-sq-metre artificial pavement at a research centre called [[Pedestrian Accessibility and Movement Environment Laboratory]] (PAMELA). It is used to simulate everyday scenarios, from different pavement users to varying pavement conditions.<ref>{{cite news| url=http://news.bbc.co.uk/1/hi/sci/tech/5333936.stm | work=BBC News | title=Scientists walk on tech pavement | date=12 September 2006 | access-date=22 May 2010}}</ref> There also exists a research facility near [[Auburn University]], the [[NCAT Pavement Test Track]], that is used to test experimental asphalt pavements for durability.

In addition to repair costs, the condition of a road surface has economic effects for road users. [[Rolling resistance]] increases on rough pavement, as does wear and tear of vehicle components. It has been estimated that poor road surfaces cost the average US driver $324 per year in vehicle repairs, or a total of $67 billion. Also, it has been estimated that small improvements in road surface conditions can decrease fuel consumption between 1.8 and 4.7%.<ref>{{Cite web|url=http://digitalmagazinetechnology.com/a/?KEY=betterroads-11-08august&fp=38&title=August%25202011#page=7 |title= The Value of Smooth |work= Better Roads |date = August 2011 |publisher= Randall Reilly }}</ref>

==Markings==
{{Main article|Road surface marking}}
Road surface markings are used on paved roadways to provide guidance and information to drivers and pedestrians. It can be in the form of mechanical markers such as [[Cat's eye (road)|cat's eye]]s, [[botts' dots]] and [[rumble strip]]s, or non-mechanical markers such as paints, [[thermoplastic]], plastic and [[epoxy]].

==See also==
{{div col|colwidth=18em}}
* [[Asphalt concrete|Asphalt]]
* [[Cobblestone]]
* [[Diamond grinding of pavement]]
* [[Ecogrid]]
* [[Good Roads Movement]]
* [[List of road types by features]]
* [[Pavement management]]
* [[Plastic armour]]
* [[Portuguese pavement]] (mosaic-like)
* [[Road construction]]
* [[Road slipperiness]]
* [[Sealcoat]]
* [[Sett (paving)]]
{{div col end}}

==References==
{{reflist}}

==External links==
*{{Commons category-inline|Pavements}}
*[http://www.paveshare.org PaveShare - Concrete Paver Education]
*[https://www.fhwa.dot.gov/pavement/index.cfm "Pavements" website of the US Department of Transportation's Federal Highway Administration]
* {{cite book |doi=10.1787/9789282108116-en |title=Long-life Surfacings for Roads |series=ITF Research Reports |year=2017 |isbn=978-92-821-0810-9 }}

{{Road types}}

{{Authority control}}

{{DEFAULTSORT:Road Surface}}
[[Category:Pavements]]
[[Category:Road hazards|Surface]]
[[Category:Articles containing video clips]]