The potentially licence-saving technology uses a forward-looking camera to read speed limit signs as well as ‘no overtaking’ signs. An image of the road sign is then shown on the Volvo V40's central instrument display until the next sign is detected, helping drivers in almost all situations to know the speed limit on any particular stretch of road.
If the vehicle knows it is being driven faster than the speed limit the correct speed sign will flash three times to warn the driver.
Volvo says the system has been thoroughly tested in many countries, including Australia, and while it can’t guarantee 100 per cent accuracy (poor weather conditions are among the prohibiting factors), the system worked faultlessly over several hundred kilometres during our recent launch drive of the Volvo V40 in South Australia
The system even recognises road work signs and the 40km/h signs on the back of buses, but drivers obviously still need to monitor variable speed areas like school zones.
BMW has a similar system called Speed Limit Information available in its vehicles in Europe. The system was offered in Australia, but has been deactivated since March 2011 due to reliability and accuracy issues.
The BMW system relies on the satellite navigation for speed limit information and problems arise when local councils decide to change the speed zones and the navigation system’s database is unaware of the new speed limit.
Volvo’s Road Sign Information system is available as part of the $5000 Driver Support package, which also includes Adaptive Cruise Control with Collision Warning with full auto brake, Blind Spot Information System, Cross Traffic Alert, Driver Alert and Park Assist Pilot.