Dynamic Curve Warning
Independently proven to reduce average approach speeds to curves by up to 7mph and significantly reduce the occurrence of lane departure fatalities.

Dynamic curve warning VATCS are installed in advance of the curve and work in tandem with existing static warning signage, and are targeted at specific drivers traveling above a pre-determined safe speed threshold.

Drivers are not informed what speed they are traveling, rather they are advised of the approaching curve hazard with request to SLOW DOWN, further enhanced by dynamic flashing pairs of horizontal corner beacons.

VATCS employ microwave Doppler radar to detect vehicle approach speeds and use diagrams sizes and colors that are in line with the MUTCD to ensure a consistent and clear road speed management strategy.

Importantly the VATCS are not a replacement for static signage or to be used as a repeater they area speed targeted supplementary advisory device.


Model Specific to Hazard - one size doesn’t fit all
A full range of dynamic curve VATCS models are available in ,24 x 24” (600 x 600), 30 x 30” (750 x 7500) and 36 x 36”(900 x 900) sizes ensuring the sign is appropriate for the road speed and curve type.

Independently proven - long term effective
7mp/11kph reduction on average curve approach speeds maintained after 3 years - TRL 548 report 1/3rd drop in curve accident rate after 3 years-TRL 548 report

Dynamic Corner Beacons - attract drivers attention but keep message clear
An important feature of VATCS is recognising that drivers have a limited time to read and react to a warning message. This is why VATCS incorporate dynamic flashing beacons in each corner of the display to attract driver’s attention whilst importantly maintaining the warning message steady for 3 seconds.

MUTCD compliant - consistent approach
VATCS are in full compliance with the MUTCD and where deployed support a clear, consistent speed management strategy of already recognized static regulatory and warning signs.

Federally Tested
VATCS is the only traffic calming display technology that has been federally field tested on a large scale to prove long term effectiveness, with driver respect of the technology being maintained over a 5 year period.

Targeted Message - Drivers wont tune out and respond well to reasoned message
When not active VATCS blend into the background, drivers are only provided a warning when their speed dictates it to be necessary. It is proven that the best overall driver behavior change is attained when drivers see the message is reasoned and well thought out.

Clear Message - Drivers informed of the curve hazard ahead and requirement to Slow Down
Importantly drivers aren’t told what speed they are traveling at, rather when required they are clearly informed of the curve hazard ahead and the requirement for them to slow down to safely manoeuver the curve.

In addition to TRL548 report , dynamic curve warning VATCS displays were also selected to be nationally tested by FHWA across 8 states and are steadily becoming the common sense approach of choice for display based traffic calming across North America.

Related Pages
Case Studies
  • Preventing accidents and improving life within your local community.

  • Large Scale Evaluation of VATCS - Preventing accidents and improving life within your local community.

Jerry Britton

T: +1 613 352 3458
C: +1 613 583 9988
F: +1 613 352 6845
E: jerry.britton@unipartdorman.com