Study shows reduced speeds on Highway 23

Roundabout, lane changes effective in Foley

BY Jakob Kounkel | STAFF WRITER
Posted 5/30/23

FOLEY – After the Highway 23 road construction that consumed the summer of 2022 in Foley, the contours of the highway have given way to a safety-focused overhaul.

Leaving the city with its first roundabout on its most popular road, the Minnesota Department of Transportation reported that the alterations in traffic control have been effective thus far.

MnDOT completed a speed study on Highway 23 at the end of last year, and it found that driver behavior changed in reaction to the roundabout and reduced lane width, among other alterations, with reduced speeds.

Even though MnDOT has attempted to reduce speeds in the past with signage changes, crashes and other traffic incidences continued apace. However, after construction was completed for the year, MnDOT intentionally did not place speed limit signs along the highway.

As the state’s transportation department studied driver behavior, it found that the changes in the context of the roadway – the roundabout, narrowed lanes, sidewalks, and curb and gutter expansion – proved more effective than signage. Even without signs indicating what speed drivers should be traveling, traffic slowed; whereas, without the context changes and with speed limit signs, traffic speeds remained too fast.

“Signs alone don’t change driver behavior,” said Ken Hansen, a MnDOT traffic engineer. “We really try to change roadway context and geometry so you don’t have to have a patrol officer out there continuously to get speeds to what we and the citizens want.”

For example, one of the reasons roundabouts have become so popular is because the geometry of a roundabout forces drivers to slow their vehicles to feel comfortable driving through them, Hansen said.

He also said elements like the number of buildings and entrance points, the distance of building setbacks and pedestrian activity also influence driver behavior more effectively than signage alone.

“It’s hard to get drivers to change behavior without outside influence,” Hansen said. “We want the roadway to self-enforce, which is a newer concept. We don’t want the speeds to be driven by (police officers) enforcing those.”

An example relevant to Highway 23 is the stretch of the road between Foley and Ronneby. Hansen said the areas along the roadway are wide open, with few houses and an abundance of agricultural land and trees. Drivers are more likely to reach speeds above the limit in that area.

West of Highway 23, which travels through a more urbanized section of Foley, Hansen said the roundabout has proven effective at slowing speeds for both eastbound and westbound traffic near Foley Public Schools – a victory for concerned citizens in Foley.

In collecting data, MnDOT technicians used a radar device to track the speed of passing vehicles from a nearby parking lot, or an area that would not influence the speed of passersby. Although the study wrapped up in December 2022, MnDOT ensured driving conditions were perfect – no snow, ice or sand on the roads to influence driver behavior.

Hansen said it was important to study speeds during a typical weekday rather than on a weekend or a Friday, where Foley often serves as a popular passage for weekend travelers.

MnDOT looks to set speed limits around the 85th percentile of what motorists feel comfortable driving, meaning that the highest speed that 85% of drivers feel comfortable traveling is approximately the speed limit MnDOT will set.

As for the efficacy of the safety changes as it relates to crashes and traffic incidents, Hansen said MnDOT does not yet have enough data to support an effective or ineffective result. Hansen said the state uses about five years of traffic data to make an assessment.

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