meeting-place based carpooling, in which participants make their way (walk, cycle, scooter, drive) to a meeting-place, and form fuller cars in the order of their arrival. Each meeting-place is specific to one destination. There are three types of participants: those who always want to drive; those who always want to ride; and those who will do whichever works best for them on the day. There is no trip-by-trip pre-arrangement of who will ride with whom. The return journey might be by similar express carpool, or by public transport. Three and four-person carpools are as easy to form as two-person ones. Participants can make their final decision to ride or drive right up until the last moment.

Express carpooling is best understood by reference to the 'slug lines' in Washington DC, and the 'casual carpooling' in San Francisco. These systems developed organically over many years.

Raspberry Express seeks to catalyse new express carpooling routes and so achieve the benefit of this approach to carpool formation for additional cities.