Pilot project targets traffic safety on Green Mountain Drive


Excessive speeds, poor compliance with stop signs and documented crash patterns – these are the target of a pilot project to improve traffic safety on Green Mountain Drive, underway now by Lakewood Transportation Engineering.

What's involved?

We are replacing some four-way stop signs with traffic circles and yield signs for testing. A traffic circle functions in many ways like a mini-roundabout, with a small island in the center of the road that motorists must circumnavigate. The low-cost traffic circles result in a narrower road and typically slower speeds. The two intersections testing the circles are:

  • Valentine Way/Green Mountain Drive
  • Urban Way/Green Mountain Drive


Additionally, the study will look for any reductions in speeding between the traffic circles. It will also look for improvements in drivers stopping at the four-way stops at Green Mountain Drive's intersections with Wright Street and with Welch Circle, which are also part of the pilot study. 

Why Green Mountain Drive?

Green Mountain Drive from Alameda Parkway to Union Boulevard was recently repaved. With repaving projects, we typically review traffic control devices to see what changes should be considered to better serve the public’s safety and transportation needs. The test sites were selected for the pilot program because of documented excessive speeds, poor compliance with stop signs and documented crash patterns. A two-hour observation at midday and during the rush hour found the following driver behaviors:

Valentine Way: 

  • 35% (49 of 139) of all drivers did not come to a "reasonable stop," which is a full stop, or entering the intersection under 5 mph.
  • 10% (14 of 139) of non-stopping drivers showed a "malicious disregard" for stopping, making no effort to reduce speed prior to entering the intersection. 

Urban Way: 

  • 37% (77 of 206) of the drivers did not reasonably stop.
  • 10% (20 of 206) of drivers showed a malicious disregard for stopping.


  • 85% of drivers drove more than 11 mph over the posted speed limit of 30 mph, according to our 2019 traffic study.
  • 11 documented crashes in six years occurred at the Wright Street and Welch Circle intersections.


How can traffic circles improve safety?

These two intersections do not have enough side road traffic to justify the existing all-way stop signs. A common misconception is that forced stops will reduce speeding. Stop signs used in unnecessary locations typically result in only lowering speeds immediately near the stop sign but create higher speeds between intersections. Frustrated motorists have a desire to “make up” perceived lost time.

Disrespect of a stop sign results in a deadly scenario. The stop sign can create a false sense of security in a pedestrian and an attitude of contempt in a motorist. These two attitudes can combine with tragic results. 

What are our goals?

  • Lakewood Transportation Engineering is continually striving to protect neighborhoods. High speeds on local streets are dangerous for the safety of the community.
  • Our goal is to study the impact that these specific devices have on improving driver behavior and reducing speeds through a residential traffic calming pilot program. 

How will we evaluate our effectiveness?

Effectiveness will be measured immediately after installation, and in three, 3-month intervals in the following ways:

  • Before/after speed study on Green Mountain Drive between Valentine Way and Urban Way
  • Before/after stop compliance study at Green Mountain Drive at Welch Circle and Wright Street
  • General compliance observations at Valentine Way and Urban Way (e.g. yield behavior, intuitiveness of design, near misses/crashes)

We will evaluate maintenance needs to determine if the traffic control devices would be more successful with specific design modifications.

Immediately following the modification of any traffic control device, a higher risk of collisions exists as drivers modify behavior. It is important to recognize that a crash that occurs immediately after modification should be noted; however, long-term increase or decrease of crashes is what is important to observe. Before installation of these measures, variable message signs will help prepare motorists to be aware of the modifications.