One solution for public transport in suburban areas could be a "Postbus". This is a combined passenger and mail delivery service, used in rural areas, where the population density is too low for a regular bus service.
Urban areas with a high population density can use a timetable-less public transport system is generally known as a "metro". An Australian example is the Sydney Metrobus, which runs every 10 minutes
in peak times.
Where trams or buses are used the system can be used in a much lowerpopulation density than a heavier "metro" railway. However, to be
viable it still requires a population living in higher density housingthan an Australian suburb of detached houses. A typical suburb will only have enough passengers for a bus every hour, or more, at off peak times. In contrast, due to the population density, the Istanbul Metrobüs has some routes with a bus every 20 seconds.
The suburban postbus could be based at transport interchanges to servicethe surrounding suburbs off-peak. Passengers and parcels would arrive at the interchange on the same buses, trams or trains. The system would be able to transport items as large as a dishwasher (and pallets of goods for shops), but would most commonly be used for delivery of groceries and small packages ordered online.
As the postbus would cover only a small area and have a permanent depot,it could be fueled by renewable energy, either using batteries or
compressed methane. Postbusses can be as large as a regular suburbanbus, but something like a wheelchair accessible taxi, based on asmall van, would be more suitable. This could replace most off peak buses, taxis and some private cars, as well as many truck and courier deliveries.
The service would be booked by phone or via the Internet, with the customer able to negotiate time and price. The service would cost as little as a regular bus, or as much as a taxi, depending on how long the customer was prepared to wait. If the customer traveled in a booked group, the service would be cheaper than a regular bus.