Demand-responsive transport (DRT), also known as demand-responsive transit, demand-responsive service, Dial-a-Ride transit (sometimes DART), flexible transport services, Microtransit or Non-Emergency Medical Transport (NEMT) is a form of shared private or quasi-public transport for groups traveling where vehicles alter their routes each journey based on particular transport demand without using a fixed route or timetabled journeys. These vehicles typically pick-up and drop-off passengers in locations according to passengers needs and can include taxis, buses or other vehicles. Passengers can typically summon the service with a mobile phone app or by telephone; telephone is particularly relevant to older users who may not be conversant with technology.
One of the most widespread types of demand-responsive transport (DRT) is to provide a public transport service in areas of low passenger demand where a regular bus service is not considered to be financially viable, such as rural and peri-urban areas. Services may also be provided for particular types of passengers. One example is the paratransit programs for people with a disability. The provision of public transport in this manner emphasises one of its functions as a social service rather than creating a viable movement network.
DRT can be used to refer to many different types of transport. When taxicabs were first introduced to many cities, they were hailed as an innovative form of DRT. They are still referred to as DRT in some jurisdictions around the world as their very nature is to take people from point-to-point based on their needs.
More recently, DRT generally refers to a type of public transport. They are distinct from fixed-route services as they do not always operate to a specific timetable or route. While specific operations vary widely, generally a particular area is designated for service by DRT. Once a certain number of people have requested a trip, the most efficient route will then be calculated depending on the origins and destinations of passengers.
Share taxis are another form of DRT. They are usually operated on an ad hoc basis but also do not have fixed routes or times and change their route and frequency depending on demand.
Some DRT systems operate as a service that can deviate from a fixed route. These operate along a fixed alignment or path at specific times but may deviate to collect or drop off passengers who have requested the deviation.
DRT services are restricted to a defined operating zone, within which journeys must start and finish. Journeys may be completely free form, or following skeleton routes and schedules, varied as required, with users given a specified pick-up point and a time window for collection. Some DRT systems may have defined termini, at one or both ends of a route, such as an urban centre, airport or transport interchange, for onward connections.
DRT systems require passengers to request a journey by booking with a central dispatcher who determines the journey options available given the user's location and destination.
DRT systems take advantage of fleet telematics technology in the form of vehicle location systems, scheduling and dispatching software and hand-held/in vehicle computing.
Vehicles used for DRT services are typically small minibuses sufficient for low ridership, which allow the service to provide as near a door-to-door service as practical by using narrower residential streets. In some cases taxicabs are hired by the DRT provider to serve their routes on request.
DRT schemes may be fully or partially funded by the local transit authority, with operators selected by public tendering or other methods. Other schemes may be partially or fully self-funded as community centred not for profit social enterprises (such as a community interest company in the UK). They may also be provided by private companies for commercial reasons; some conventional bus operating companies have set up DRT-style airport bus services, which compete with larger private hire airport shuttle companies.
DRT can potentially reduce the number of vehicles on the road, and hence pollution and congestion, if many people are persuaded to use it instead of private cars or taxis.
For a model of a hypothetical large-scale demand-responsive public transport system for the Helsinki metropolitan area, simulation results published in 2005 demonstrated that "in an urban area with one million inhabitants, trip aggregation could reduce the health, environmental, and other detrimental impacts of car traffic typically by 50–70%, and if implemented could attract about half of the car passengers, and within a broad operational range would require no public subsidies".
DRT schemes may require new or amended legislation, or special dispensation, to operate, as they do not meet the traditional licensing model of authorised bus transport providers or licensed taxicab operators. The status has caused controversy between bus and taxi operators when the DRT service picks up passengers without pre-booking, due to the licensing issues. Issues may also arise surrounding tax and fuel subsidy for DRT services.
Ridership on DRT services is usually quite low (less than ten passengers per hour), but DRT can provide coverage effectively.
Since the mid-2010s several DRT projects started up but failed.
In the US several DRT operators appeared and promptly failed, due to either lack of customers or health and safety issues. 2019 trials in London found that "satisfaction was really high"; users scored the service at 4.8/5 and praised ease of use, safety, cleanliness and accessibility. But low take-up, misunderstandings about who the service was for, and safety concerns about unlit stops—together with problems due to the covid pandemic from 2020—caused the trials to fail.
Lukas Foljanty, a shared-mobility enthusiast and market expert, keeps track of the different DRT schemes around the world and thinks a tipping point may have been reached in 2022. There were at least 450 schemes around the world, and in 2021 fifty-four new projects started within a three-month period.
David Carnero of Europe-wide DRT technology company Padam said that successful DRT requires subsidies, must be delivered at scale, and must be part of an integrated, rather than competitive, transport policy.
Main article: cs:poptávková doprava
Main article: fi:kutsuohjattu joukkoliikenne
Red minibuses which serve non-franchised routes across the country, depending on routes, allow passengers to reserve their seats by phone such that operators and drivers are able to know where passengers are and how many there are in deploying their vehicles.
Public transport authority in the Icelandic capital of Reykjavik and the surrounding municipalities. Manages public bus transport and disabled transport, but does not have its own vehicles. About 1300 enquiries and thousand trips a day. Uses 60 vehicles and 10–20 more for school transport for children with special needs.
Following some pioneering DRT schemes implemented in the 1980s, a second wave of systems were launched from the mid-1990s. There are now DRT schemes in urban and peri-urban areas as well as in rural communities. Operated by both public transport companies and private service providers, the DRT schemes are offered either as intermediate collective transport services for generic users or as schemes for specific user groups. DRT schemes operate in major cities including Rome, Milan, Genoa, Florence, and in several mid- to small-size towns including Alessandria, Aosta, Cremona, Livorno, Mantova, Parma, Empoli, Siena, and Sarzana.
Main article: ja:デマンドバス
More than 200 of the 1700 local governments in Japan have introduced DRT public transport services.
The first ever demand-responsive transport scheme in Poland – called Tele-Bus – has been operated since 2007 in Krakow by MPK, the local public transport company (see also Tramways in Krakow).
Regional transport authority in Västra Götaland in southwestern Sweden is responsible for all public transport and for transport offers to citizens with special needs. This is an example of DRT used for people with special needs (paratransit).
DRT services have operated in some sparsely populated areas (under 100 p/km2) since 1995. PostBus Switzerland Ltd, the national post company, has operated a DRT service called PubliCar, formerly also Casa Car.
Some DRT schemes were operating under the UK bus-operating regulations of 1986, allowed by having core start and finish points and a published schedule. Regulations concerning bus service registration and application of bus-operating grants for England and Wales were amended in 2004 to allow registration of fully flexible pre-booked DRT services. Some services, such as LinkUp, only pick up passengers at 'meeting points', but can set down at the passenger's destination.
The Greenwich Association of the Disabled had earlier developed a prototype service, GAD-About, which offered pre-booked door-to-door transport for its members, inspired by similar minibus usage in church and youth clubs. That was then cloned as an easily scalable module, under the aegis of London Transport, to become the Dial-a-Ride service launched as part the general services of Transport for London (TfL), rather than as a bus service.
The large majority of 1,500 rural systems in the US provide demand-response service; there are also about 400 urban DRT systems.