Editing Carpool (section)

==Challenges==
[[File:Carpool Decline in USA.png|thumb|upright=1.5|The share of US workers commuting by carpool has declined from 20.4% in 1970 to just 9.7% in 2011.]]

* Flexibility - Carpooling can struggle to be flexible enough to accommodate in route stops or changes to working times/patterns. One survey identified this as the most common reason for not carpooling.<ref name=TX /> To counter this some schemes offer 'sweeper services' with later running options, or a 'guaranteed ride home' arrangement with a local taxi company.
* Reliability - If a carpooling network lacks a "critical mass" of participants, it may be difficult to find a match for certain trips. The parties may not necessarily follow through on the agreed-upon ride. Several internet carpooling marketplaces are addressing this concern by implementing online paid passenger reservation, billed even if passengers do not turn up.
* Riding with strangers - Concerns over security have been an obstacle to sharing a vehicle with strangers, though in reality the risk of crime is small.<ref>{{cite journal |url=http://trid.trb.org/view.aspx?type=MO&id=28681 |title=Hitchhiking: a Viable Addition to a Multimodal Transportation System: Prepared for National Science Foundation, 1975 |publisher=Trid.trb.org |date=1976-02-04 |access-date=2014-01-29 |last1=Dallmeyer |first1=K. E. |archive-date=8 November 2019 |archive-url=https://web.archive.org/web/20191108013523/https://trid.trb.org/view.aspx?type=MO&id=28681 |url-status=dead }}</ref>  One remedy used by internet carpooling schemes is reputation systems that flag problematic users and allow responsible users to build up trust capital, such systems greatly increase the value of the website for the user community.
* Overall efficacy - Though carpooling is officially sanctioned by most governments, including construction of lanes specifically allocated for car-pooling, some doubts remain as to the overall efficacy of carpool lanes. As an example, many car-pool lanes, or lanes restricted to car-pools during peak traffic hours, are seldom occupied by car-pools in the traditional sense.<ref name=":0">{{Cite web|last=Templeton|first=Brad|title=Carpool Cheats May Be Helping Traffic; How HOV Lanes Can Fail|url=https://www.forbes.com/sites/bradtempleton/2019/08/06/carpool-cheats-may-be-helping-traffic-how-hov-lanes-can-fail/|access-date=2021-04-04|website=Forbes|language=en}}</ref> Instead, these lanes are often empty,<ref name=":0" /> leading to an overall net increase in fuel consumption as freeway capacity is possibly contracted, forcing the solo-occupied cars to travel slower, leading to reduced [[fuel efficiency]].{{citation needed|reason=See [[Braess's effect]]|date=October 2019}} 
* In 2012, the Queensland government announced it would end carpool lanes (known as Transit Lanes) claiming they were creating congestion and delays. The move was supported by the [[RACQ]] motoring group.<ref>{{Cite web|url=http://media.smh.com.au/news/national-news/transit-lanes-create-congestion-and-delays-3723415.html|title=Transit lanes video{{!}}RACQ backs plan to scrap T2 lanes, Brisbane|date=2013-12-22|archive-url=https://web.archive.org/web/20131222023638/http://media.smh.com.au/news/national-news/transit-lanes-create-congestion-and-delays-3723415.html|archive-date=2013-12-22|access-date=2018-04-03}}</ref>
* No carpooling service provides the ability for drivers to declare the time range during which they provide services in advance. Although the majority of carpooling services use a mobile application, this is not the case for interurban carpooling services (i.e., Ride joy and Autostrade carpooling){{citation needed|reason=What are the main differences?Are there any pros and cons?|date=August 2024}} . In addition, no carpooling was found to guarantee a minimum delay for drivers or a single dropoff/pickup point. Some carpooling platforms (i.e., TwoGo and BlaBlaLines operated by BlablaCar) use an intelligent technology to analyze rides from all users to find the best fit for each user. This intelligent technology even factors in real-time traffic data to calculate precise routes and arrival times.<ref>{{cite journal| journal=Sustainability | first1=L.| last1=Mitropoulos | first2=A. | last2=Kortsari |first3=G. | last3=Ayfantopoulou | title=Factors Affecting Drivers to Participate in a Carpooling to Public Transport Service | date=2021-09-01| volume=13 | issue=16 | page=9129 | doi=10.3390/su13169129 | doi-access=free }}</ref>