COLUMBIA — After reviewing the results of an MU traffic study, the Columbia Public Works Department is recommending that the City Council lower speed limits on all residential streets in Columbia.
The study was conducted by MU civil engineering researchers and measured the effects of lowering residential speed limits from 30 to 25 mph.
Reducing speed limits caused a "statistically significant" reduction in traffic speeds in the neighborhoods, the study states.
Columbia Supervising Traffic Engineer Scott Bitterman was tasked with reviewing the results and making a recommendation to City Council. He said the key part of the study to consider was residential traffic volume.
Although the decreased speed limits in neighborhoods caused people to drive slower on average, it also led to an increase in speed variability — more people driving at different speeds.
On high traffic roads, speed variability can cause drivers to make riskier maneuvers, such as passing cars in non-passing zones, because of the inconsistent pace, the study states.
Bitterman says this won't be a problem, however, on Columbia's low-volume residential roads. Even if speed variability is increased, he said, there isn't a high enough volume of traffic to create problems.
"What this says to me is that you can lower speed limits on lower volume streets," Bitterman said.
The study was conducted earlier this year in the Rothwell and Shepard neighborhoods, where MU researchers, led by associate engineering professor Carlos Sun, placed magnetic traffic detectors on randomly selected streets. The study was funded with $10,000 of city money.
After recording traffic habits at the 30 mph posted speed limit, city workers replaced speed limits signs with new, lower limit signs.
In addition to recording the effects of reduced speed limits, the researchers also worked with the PedNet Coalition to create an educational campaign for neighborhood residents.
The results of the study, and the Public Works Department's recommendation for lower speed limits, will be reviewed by City Council at Monday night's meeting.