Terminology
The concepts of ride sharing is not new, but there is great disparity between the way schemes have been developed in different countries. The disparity includes differences in terminology. Ride sharing can be loosely defined as any process which facilitates a car driver giving a lift to another person. This can range from informal lift giving between friends and family to a formally organised workplace scheme for journeys to and from work. Ride sharing (a European term) is variously known as lift giving, car pooling (in North America) and car sharing (in the UK). In the UK, a car pool is the term used to describe the situation where a company owns one or more vehicles for use by its employees on company business as and when needed.

Ride sharing differs from a car club in that the former requires drivers to possess their own vehicles. Where as members of a car club do not need to possess their own vehicles. Drivers become members of a club from which they can hire a vehicle for short periods. The passengers who participate in ride sharing can be other car owners or non-car owners.

Styles of Ride Sharing
Informal lift giving between family and friends. This includes parents driving children around, e.g. to school, a neighbour giving an elderly person who cannot drive a lift to the supermarket when they go, or one person driving a group of friends to the cinema for example. The role of informal lift giving in meeting transport objectives consequently varies tremendously. Parents driving their children to school contributes significantly to peak hour congestion, hence efforts are being made to reduce this type of escort journey. One parent driving several children from different households could contribute to reducing car use, where alternatives are impractical. Such measures to tackle the school run form part of school travel plans and are dealt with under that measure. A neighbour giving an elderly person a lift to a supermarket when they themselves would travel regardless probably has little impact on the car use. However, it could reduce the burden on social services if the elderly person were otherwise unable to shop independently. On the other hand, informal lift giving for social activities can reduce road traffic relative to the situation that would occur if four individuals drove to the same destination independently.

Ride sharing for work. This can also be an informal arrangement within a household, between colleagues or neighbours, or it can be a formal arrangement through the workplace. Formal workplace schemes are promoted as a means of reducing peak hour congestion, and other negative impacts of car travel, frequently promoted through company travel plans. Ride sharing can also reduce demand for expensive long stay city centre parking spaces and/or on site parking at a business location, both of which can be in short supply. This is probably the most common form of organised ride sharing.

Ride sharing through matching services. Ride sharing can be organised through services designed to match drivers and their journeys to passengers wishing to undertake particular journeys. These services usually operate through a database of drivers and passengers. Such services can start as small community initiatives operated on a paper basis, but increasingly, they are accessed via the Internet and serve a wider area. However, such advances have also brought concerns about security, both personal and of data, so up take can be very low.

The ride sharing outlined above is designed to reduce car use. Ride sharing can also be promoted to increase accessibility for potentially disadvantaged groups. In addition to the mechanisms outlined above, ride sharing to increase accessibility could be facilitated by community groups, especially in rural areas or by government bodies established to increase access to jobs, education and healthcare.

Charges
Charges for ride sharing are generally low, but vary depending on the mechanism by which the matching service is accessed. For work based schemes designed to facilitate ride sharing for the journey to and from work, access for individual users is generally free and the cost of setting up the matching service is absorbed by the company. Alternatively, organisations (not solely employers) can become corporate members of independent matching services - i.e. the organisation pays the service provider to administer their matching service. Some service providers then charge a registration fee per participant, which the organisation could pass onto the individuals. Further details of ride sharing schemes for the journey to and from work can be found in the Company Travel Plan section.

Where individuals wish to become members of an independent ride-matching service, there is usually a small annual membership and/or registration fee, plus a charge per journey. Groups of individuals who are known to each other and wish to join as a private group can also become corporate members. Some UK examples are:

• National CarShare (http://www.nationalcarshare.co.uk):
  
  • £29.95 ($42.55) registration fee (incl VAT and first year's membership)
    
  • £12.50 ($17.76) annual subscription after the first year (incl VAT)
    
  • £1 ($1.42) pick up fee per journey
    
  • £0.10 ($0.14) per mile petrol money.

• Liftshare (http://www.liftshare.com):
  
  • Free to use
    
  • Cost per journey at discretion of driver and passenger

• Shareajourney (http://www.shareajourney.com):
  
  • £9.99 ($14.19) annual membership fee
    
  • Cost per journey at discretion of driver and passenger

Figures correct at time of preparation (28/02/02).

All of these are internet based, national matching services. Others are area based, such as londoncarshare (http://www.londoncarshare.co.uk), which has no registration or membership fee and journey costs are at the discretion of drivers and passengers. In contrast to the local area based sites, others are developing with continent wide catchment areas. Examples are EuroLift (http://www.eurolift.com) for Europe and eRideShare (http://www.erideshare.com) for North America. For informal sharing between friends, colleagues or relatives charges can range from zero, or payment in kind, e.g. a lift in return where journeys are short and or lifts are regularly shared. Alternatively, the petrol costs for longer, one-off ride-shares may be split 50/50.

Technology
The technology needed to facilitate ride sharing is minimal. At the informal level, ride sharing can be facilitated through personal contact. However, it is usual to make use of a database and some form of telecommunications to initiate contact between ride sharers who may not know each other. Workplace matching systems and independent services usually rely on a database. The independent services are usually accessed via the internet and/or telephone. Workplace schemes are often based around a database built using an organisation's existing software, or a purpose designed system is bought in. More detail on this can be found in the Company Travel Plan section.

Which database is used to set up an independent matching service or which service provider is used, is largely a matter of personal choice. The criteria included in the database are more important. Matching should not be based purely on where ride sharers are travelling to and from. Some individuals may not want to travel with a smoker, some may not want to travel with somebody who listens to rock music first thing in the morning, some people may wish to travel with somebody of the same sex. Nevertheless, the location matching criteria need to be more detailed than the a postcode or zip code. Sharing with somebody on the other side of the same postcode or zip code district may not be feasible, but would be with somebody living in the next street. Alternatively, a regular driver could pick up a passenger from a completely different area along route. It is likely that a database including start and destination street, plus an indication of route would be most appropriate. However, most internet based matching services do not provide this level of detail. The journey start point and destination are usually expressed in terms of area, it is then down to potential sharers to make contact and establish whether there is a suitable meeting and drop off point. For one-off journeys this is likely to require planning well in advance to allow time for making alternative arrangements if a suitable ride share is not available.