Crystal Valley Parkway

Changes are coming in July to Crystal Valley Parkway

Safety is a priority for the Town of Castle Rock. For many, the thought of safety conjures up ideas of firefighters and police officers, but it also means appropriate traffic control, like speed limits.

The Public Works Department studies traffic throughout Town and takes actions to keep the community safe. Sometimes, that includes installing new stop signs, or new crosswalks. Sometimes that means changing the speed limit. That is the case along Crystal Valley Parkway.


Not that long ago, Crystal Valley Parkway was a two-lane road, which had a speed limit of 35 mph. Now, the road has been widened to four lanes and a median, so Public Works needed to reevaluate. The department recently studied speeds along Crystal Valley Parkway between the new Fire Station and Lake Gulch Road. The results showed a majority of people driving faster than the posted speed limit, due to the widened roadway.

Speed limit changes

As a result of the study, and following nationwide best practices for setting reasonable speed limits, the Town is increasing speed limits along a portion of Crystal Valley Parkway. The new limit is more in line national standards for speed limits and safety.

Changes include:

  • Increasing the speed limit to 45 mph between Lake Gulch Road and Manorbrier Circle, and Plum Creek Boulevard and Wilcox Street / Frontage Road.
  • The existing 35 mph speed limit will be maintained between Plum Creek Boulevard and Manorbrier Circle due to limited sight distance for turning vehicles at Old Lanterns Parkway.
  • Installing a supplemental pedestrian crossing, a push-button activated rapid flashing rectangular beacon (RRFB) with advanced warning, at Old Lanterns Parkway. RRFB’s have been installed around Town to alert drivers a pedestrian is ready to cross.
  • Installing advanced warning signs, some with amber flashing beacons, warning drivers about the reduced speed limit area and of turning vehicles at some intersections. 
View a map of the changes.

Facts that might surprise you about speed limits

  • Traffic studies show most people will drive the roadway as they perceive the conditions and ignore a speed limit that is unrealistically high or low.
  • Speed-related accidents are more likely caused by speed differentials, not a high or low speed.
  • A realistic speed limit is voluntarily obeyed by the reasonable majority, which helps with enforcement.
  • An unrealistic speed limit that is too low will: make the behavior of the majority unlawful; cause antagonism toward law enforcement; create a bad image of the community; and result is significant speed differentials in traffic flow.
  • Reducing the speed limit along a street will not automatically slow the speed of traffic, and increasing the speed limit will not automatically cause an increase in speed. Studies show it is generally at the upper boundary of a speed range where crash involvement rates are the lowest.