Real-time information at bus stops
Real Time Information is frequently displayed at bus stops. (The first wave of real-time passenger information was at bus stops). The main objective is to give the traveller some certainty about when a bus will arrive. Sometimes it provides them assurance about the service they had intended to take; other times they can use this information to make a choice about taking an alternative service.
Most at-stop real-time information systems are multi-line displays that display information about the next 2-4 buses expected to arrive at the stop. The information includes:
- For each forecast arrival at the stop, the most typical information is:
- Route Number, and variant if applicable
- Forecast arrival time at the bus stop; or
- Number of minutes to the arrival
- Optionally, there may be additional symbols to indicate:
- Whether the vehicle is in delay
- Whether the vehicle is wheelchair accessible/low floor – this is used in cases where there is a mixed fleet
- Indication of vehicle type, sometimes used when there are different door/boarding arrangements
- For stops with multiple routes, there are variants on which arrivals are displayed:
- The next vehicles in order of arrival, regardless of route
- The next vehicle to arrive on each route (subject to the maximum number of routes that can be displayed)
- To overcome the limitations of the number of lines on the display, the following methods are used to increase the amount of information available to the passenger
- Both the next and subsequent arrival for the same route are shown on one line
- The last line of the display scrolls through the subsequent 2-4 arrivals
- Traveller alerts
- Current delays and disruptions
- Events that are expected to happen later in the day (e.g. demonstration) or in the coming days (e.g. diversion due to construction/roadworks)
- Forthcoming route and timetable changes
- Specific messages initiated by the CAD/AVM dispatcher
- Safety and security messages
- Commercial advertising (still relatively rare)
Technologies, data and resources
Real-time information at bus stops mostly use multi-line displays. Alternatives include computer-style screens with high graphic capability, or units where most of the information is fixed (route, destination) and a small area displays the number of minutes to next arrival.
Communications to the display unit can be by landline, radio, or GPRS.
Power is usually by cable, although some units are solar powered.
The primary data required for the real-time information is derived from the CAD/AVM system. A software program or algorithm is also required to forecast the arrival time - based on the current location of the vehicle, the number of minutes forecast to reach the stop. Ideally, this will derive the forecast from the current travel times (thus taking account of actual variances from the schedule). In practice, it is often simply based on the scheduled sectional running times to reduce the software development and computational burden.
A database of all stops and associated routes is required.
Advantages and Cautions
The primary advantages of Real-time Information at Bus Stops are to:
- Provide information to travellers at their waiting area (waiting time is shown to have the highest negative value, and uncertainty causes anxiety)
- Increase travel choices for travellers
- Communicate directly to travellers while they are in transit
The principal cautions in relation to Real-time Information at Bus Stops are:
- The units are expensive, and this limits their deployment to the busier stops. Increasingly, transit authorities and operators are reflecting on the balance between information at bus stops and information via personal mobile devices.
- Due to their outdoor location, readability can be a problem in varying light conditions. This can be a real problem when there is not a bus shelter, as the display unit may be in full sunlight
- Units need to be robust and resistant to both weather and vandalism
- Communications and power supply can be a challenge, in part for availability, In part due to permissions required for works on public pavements and space. This is sometimes overcome by transferring the responsibility for the installation works to the local authority.
Relevant Case Studies
Dublin, Florence, Mysore, Zurich