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Speed Limit Observation and Warning System

Roads has acquired new, high-tech Speed Limit Observation and Warning System (SLOWS) trailers in response to Calgarians' concerns about the potential for speed-related collisions in residential communities.

SLOWS are stand-alone, radar-equipped devices that display the speed of oncoming vehicles. Unlike hand-held radar units, they do not require continuous hands-on operation by city staff/community volunteers.


The SLOWS program:

  • Enhances traffic safety by educating motorists about how fast they are going and encouraging self-correction. 
  • Conveys community concern about speeding.
  • Balances enforcement activities with an educational component.
  • Allows community associations to take a proactive approach to traffic safety by enabling them to request the placement of a Speed Awareness trailer in an area of their community where speed is a concern.

SLOWS can also be used to increase driver awareness about the importance of speed limit compliance in construction zones.

SLOWS are durable, easy to move from one place to another and technologically advanced (features include: on-site keypad and remote programming, a built-in solar regulator, a 50-watt solar panel and an alarm system to prevent vandalism).

How does a community association request a SLOWS?

Community associations can request the placement of a SLOWS trailer in an area where speeding is a concern by filling out the online service request below.

eServices - Request a Speed Trailer Sign 

Signs in the community

ISLOWS signInteractive Speed Limit Observation and Warning System (ISLOWS) solar powered signs are installed in various communities throughout Calgary each year to alert motorists if they are driving faster than the posted speed limit. The signs are installed at specific locations where our speed studies have shown issues and change annually.