BC Variable Speed Limit System

Driving the highways of British Columbia can be challenging, as they pass through mountainous terrain and multiple climatic zones. In 2014, BC’s Ministry of Transportation and Infrastructure identified three highway corridors that are particularly affected by changing and adverse weather conditions through the Rural Highway Safety and Speed Review:

• Sea to Sky Highway 99: Squamish to Whistler (30km)
• Coquihalla Highway 5: Portia Interchange to former Toll Plaza (40km)
• Trans-Canada Highway 1: Sicamous to Revelstoke (30km)

Developed by IBI Group, the Variable Speed Limit System (VSLS) measures road-weather and traffic conditions 24/7, and transmits the data to the Ministry’s Advanced Transportation Management System (ATMS) – which was also designed and deployed by IBI Group – operated out of the Regional Transportation Management Centre (RTMC). A total of 47 high-tech digital signs were installed on three highways.

This system analyzes data from an extensive network of traffic, pavement and visibility sensors in real-time and uses a sophisticated algorithm to calculate appropriate speed limits and alert the RTMC operators to accept the system recommendation or over-ride it. The accepted speeds are used to update the speeds shown on the digital signs, to keep drivers aware of safe driving speeds during adverse weather conditions, congestion, or during construction and maintenance activities.

The Variable Speed Limit System software supplied by IBI Group enhances the monitoring and control capabilities of the Ministry’s Regional Transportation Management Centre, and leverages their investment in the Advanced Traffic Management System which IBI Group supplied to the province in 2014. Based on the success of this system, the BC Ministry of Transportation and Infrastructure has commissioned IBI Group to expand the system to three new corridors.