Dakota County works to keep vehicle accident numbers down by creating and maintaining a safe system of roads. One place where safety is especially important is at intersections.
In the last five years, Dakota County has had 243 fatal and serious injury crashes at intersections—47 percent of those crashes occurred at intersections with traffic signals even though only 10 percent of intersections have a signal.
Traffic signals play an important role in our transportation system, but there are other ways to control traffic. Dakota County does an assessment of intersections, looking at traffic volumes, delay and overall operation to determine what traffic control to use. Guidelines for installing a signal are provided by the Minnesota Manual on Uniform Traffic Control Devices produced by the Minnesota Department of Transportation.
Different intersections need different types of traffic control. In many cases, signals are not the best option to keep traffic moving and drivers safe.
- Two-way stops: Best used at major highway intersections with minor roadways and city streets.
- Roundabouts: Best used with equal volume roadways
- Four way-stops: Best at intersections with mid-level traffic volumes and approximately equal traffic volumes from both roadways.
- Traffic signals: Offer the highest level of traffic control in an intersection. Traffic signals are best used at intersections where major highways intersect.
The wrong traffic control can lead to more crashes
The type of traffic control at an intersection affects the frequency of traffic crashes. Intersections with traffic signals have higher crash rates than intersections using other traffic control methods. For example, crash rates at signalized intersections two times higher than at two-way stops. That’s why it’s important to install traffic signals only when they’re needed.
The cost of traffic signals
Installation of a single traffic signal costs approximately $250,000 — that’s $62.5 million for the County’s 250 traffic signals. That doesn’t include any road improvements to allow the signal to work properly.
Operating a single traffic signal costs $1,800 annually—or a total of $450,000. Dakota County has taken steps to reduce operating costs by about $90,000 per year by switching to LED lights in traffic signals, but we still want to make sure tax dollars are not funding unwarranted traffic signals that cost you more money and have the potential to make you less safe and stuck in traffic.
Dakota County only recommends and installs traffic signals when they are needed to keep people moving.