An innovative scheme integrating wireless vehicle detection traffic signals, vehicle activated signs (VAS), and a ‘hurry call’ system has reconfigured a Scottish hospital junction to address safety concerns and assist ambulance response times.
Tasked with improving safety for the 11,400 motorists who use the junction between Borders General Hospital and the Melrose Bypass (A6091) daily, UK traffic technology developer Clearview Intelligence worked in partnership with Transport Scotland and road operator Amey to install a combination of road safety solutions to control the flow of vehicles without jeopardizing response times for ambulances. The installation of the traffic signals reconfigured the junction so that, for the first time, traffic could turn right when exiting the hospital. Previously this was a left-turn-only junction, creating risks when ambulances were forced to turn right as they responded to emergency calls.
The solution centered around the installation of Clearview’s M100 wireless vehicle detection solution, which offers the same functionality as a traditional inductive loop. As the sensor is a stud fitted in the center of the lane, it is faster to install than a loop, requiring neither ducting nor trenching; instead only a single hole needs to be cored. No power source is needed. Using a magnetometer, the M100 detects vehicles waiting at the junction and wirelessly transmits the information to an M110 access point, which is a two-way communications point mounted to the traffic signal. The access point then relays the sensor detection data to the traffic signal controller, to manage the light sequence.
Whilst effective in managing vehicles through the junction, the traffic signals posed a risk for ambulances delayed in queueing traffic when leaving the hospital to respond to call-outs. To mitigate this, a hurry call button was installed, enabling ambulance staff to manually override the traffic sequence to keep the signal on green. Once the button is activated, it triggers an alert to road users, using the VAS, to inform them that an ambulance is responding to an emergency. The same sign also serves a secondary purpose, promoting the newly reduced speed limit of 50mph (80km/h) by warning drivers who are exceeding the threshold to slow down.
“The most obvious solution to this scenario, and the one most favored by locals, was to introduce a roundabout. However due to limitations caused by the size of the area and other buildability constraints, this was not possible. If it had been, it would have involved lengthy delays and disruption to the busiest junction in the Scottish Borders,” explained Jim Reid, Amey’s road safety manager for the Scottish Trunk Road South East division. “By sourcing an alternative which combined various technical solutions, we have achieved the overall objective of improving road safety without having to enforce any road closures.”
Chris Keenan, Clearview’s general manager for Scotland, added, “The challenge was to address road safety concerns by controlling the flow of traffic, but without impeding the egress for ambulances on an emergency call-out.”