Transport for London has begun early market engagement for the potential retrofitting of automated vehicle speed monitoring and driver vigilance devices to the Tramlink light rail fleet. This follows a fatal accident on November 8 2016, when a tram travelling at approximately 70 km/h on a section of line with a speed limit of 20 km/h derailed on a curve at Sandilands Junction in Croydon. Seven passengers were killed and 51 injured.
TfL’s London Trams division envisages that an Automatic Vehicle Speed Monitoring system could be fitted to ensure compliance with speed restrictions in place for specific locations and travel directions. The AVSM would generate an audible and visible alert to inform the driver if a tram exceeds the speed limit for a configurable duration, and would apply the brakes if the alert is not cleared within a specified time period or if the permitted speed is exceeded by a ‘gross margin’.
The driver vigilance functionality could be a stand-alone system, or incorporated within or interfaced to the AVSM. It would generate a vigilance alert and inform the driver if no activity is detected for a configurable period, applying the brakes if the driver does not respond.
Good news for public safety and the future of light rail, as is the tram ‘Heads Up Display’ development. Trams cannot continue to exist in a bubble isolated from the trends of greater automation and driver assistance and supervision technology evident in both road vehicles and the heavy rail sector. Tram drivers are not uniquely more immune to human errors. This does not have to be a great economic burden on light rail as some may claim. It is better characterised as a pragmatic exploitation of the falling costs and greater ubiquity of computing and communications technology. Features such as adaptive cruise control and automated parking are appearing as standard on quite modest road vehicles today for example. I would never call for ‘full (heavy rail style)’ signalling and ATP on light rail, but innovative simpler systems that can provide appropriate solutions must be possible, and might also find economic further application on ‘lighter’ segregated rail lines where full heavy rail standards apply today.