Precision Docking / Station Docking Guidance
Precision docking systems allow the driver to park or dock the vehicle in an exact location. It is primarily used to ensure that the vehicle aligns precisely with the platform edge at bus stops. In turn, this ensures that there is minimal gap between the platform edge and the doors, which facilitates smooth, safe and efficient boarding/alighting.
The precision docking system also assists the vehicle to stop in the correct place, so that the vehicle doors are aligned with the designated point on the platform. In situations such as BRT, the platform may be enclosed with a set of platform doors corresponding to the vehicle doors.
Technologies, data and resources
There are already many non-ITS technologies to assist precision docking. The most basic technology is the ‘Kassel Kerb’ which allows the wheel of the vehicle to make contact with the edge so the driver has the sensory feedback to position the vehicle correctly, but as the kerb is curved it does not cause tyre damage nor does the edge of the vehicle scrape against the platform.
The most common form of low-technology docking guidance is a small lateral guide wheel attached to the steering arm. When this comes in contact with the kerbing, it steers the vehicles along the required alignment.
ITS-supported precision docking consists of two main technology types:
Optical guidance, where the travel path is marked out on the roadway and is ‘read’ by an optical sensor located at the front of the vehicle.
Magnetic sensors, where a loop/wire or permanent magnet guidance studs are embedded on the roadway along the path to be followed. Sensors on the undercarriage of the vehicle detect the loop/studs and guide the bus along the alignment.
In both cases, the sensor technology is integrated with the steering system of the vehicle.
Advantages and Cautions
The primary advantages of Precision Docking systems are to:
- ensure that vehicles dock precisely every time
- facilitate faster boarding and alighting, thus increasing both vehicle and passenger throughput at stations
- improve the accessibility for people with mobility challenges
- facilitate tighter design, and in some occasions enabling a design solution that could not be reliably achieved without such support
- reduce the technical driving burden from drivers
The principal cautions in relation to Precision Docking are:
- optical and magnetic precision docking systems are significantly more expensive than mechanical methods
- technical and reliability issues remain with some precision docking systems
- the street-side infrastructure must be correctly installed and maintained
Relevant Case Studies
Not observed in the Case Studies
Relevant examples in Castellon, Spain; Rouen, France