CITRUS HEIGHTS, CA (MPG) - At the October 22 City Council meeting, City Engineer Leslie Blomquist and Sergeant Shaun Gualco of the Citrus Heights Police Department (CHPD) recommended an amendment to the Municipal Code for updated speed limits.

Sergeant Gualco explained that the goal of CHPD’s traffic enforcement efforts is to improve safety on city roadways through education, engineering, and enforcement. The top collision factor in the city is unsafe speed, and speed enforcement accounts for approximately 71% of all moving violations (excluding photo red light enforcement).

The most effective form of speed enforcement is Lidar, which uses a laser to accurately pinpoint specific vehicles. Lidar can be used in all traffic conditions, even on high-volume, multi-lane roadways. Sergeant Gualco said that use of Lidar requires justifiable speed limits based on valid Engineering and Traffic Surveys conducted within five years. If those conditions are not met, speeding tickets issued based on Lidar are at risk of “speed trap” legal challenges.

There are some exemptions: Speed traps don’t apply to residential streets or school zones, nor to moving violations where the officer confirmed vehicle speed through pacing (matching the vehicle speed).

Under the California vehicle code, posted speed limits should be established near the 85^th percentile of free-flowing traffic, which is the speed 85% of all drivers are traveling at or below. A speed limit can justifiably be lowered by 5 miles per hour (mph) below the 85^th percentile if the roadway has a high crash history, multiple driveways, or the presence of pedestrian or bicycle lanes.

To determine the 85th percentile of speed, data collection must be completed according to the following guidelines: Unmarked vehicles monitor the free-flow speed of vehicles on the roadway. Vehicle speed cannot be influenced by anything other than the roadway geometry. Data cannot be collected when vehicle speed is influenced by buses or trucks, traffic enforcement (or the perception of enforcement), road construction or lane closures, or inclement weather.

Engineering and Traffic Surveys were conducted on many city roadways, and based on the data collected, five speed zones were identified as requiring updated speed limits.

Three areas with posted speed limits of 40 mph are recommended to increase to 45 mph: Antelope Road from I-80 to Auburn Blvd., Antelope Road from Auburn Blvd. to Sunrise Blvd., and Sunrise Blvd. from Antelope Road to the northern city limits. In these areas, the 85^th percentile speed was measured at 51, 50, and 49 mph, respectively, which would have indicated posted speed limits of 50 mph. However, high collision rates (respectively, 237%, 165%, and 121% of the expected rate for this road type) justified a rate 5 mph below the 85^th percentile.

Old Auburn Road from Fair Oaks Blvd. to the northeastern city limits is recommended to increase from 35 mph to 40 mph, based on an 85^th percentile speed measured at 43 mph—rounded down to the nearest 5 mph increment, as allowed by state guidelines.

Only one area was recommended for a decreased speed limit: Fountain Square Drive from Greenback Ln. to Stock Ranch Rd. has a current posted speed limit of 30 mph, and the 85^th percentile speed was measured at 30. However, based on a higher than normal collision rate on this roadway (265% of the expected rate for this road type), the proposal would reduce the speed limit for this area to 25 mph.

Blomquist explained that studies have shown that setting speed limits too high or too low can increase collision rates, which is why it is so important to get accurate data through the Engineering and Traffic Surveys. Adjusting the posted speed limits based on current, accurate data “will allow for a robust and effective speed enforcement program, essentially making sure we have all the tools in our tool box to address speeding and traffic safety on our roadways,” said Blomquist.

Councilmember Bret Daniels was surprised to learn about the high level of crashes along that segment of Fountain Square Dr. and asked if those crashes were occurring at the roundabout at Stock Ranch Rd.

Blomquist explained collisions are not reported at the roundabout, but along the area of roadway in front of City Hall and the Post Office.

Councilmember Daniels supported the proposed changes to the speed limits as “very reasonable.” In particular, the areas where increased speed limits were proposed, Daniels noted that the roads are wider and well-maintained, and thus more suited for higher speeds: “I think this is a good thing, and a very logical thing for us to do. ... I think these are good changes.”

The City Council voted unanimously to approve the speed limit amendments to the Municipal Code. The costs to install new speed limit signs is approximately $6,500, which will be funded with existing, budgeted maintenance funds.