By Bryant Ficek, PE, PTOE
For a city traffic engineer, nothing signifies the end of summer quite like the barrage of calls from concerned parents (and sometimes school officials) requesting school speed zones and safety improvements. With so much at stake and so many factors to consider, school speed zones can easily become one of the more difficult projects that a traffic engineer encounters. We’ve been involved with several of these projects lately, and have identified some best practices that may be helpful to anyone else taking on these incredibly important projects.
Why do we need school speed zones?
We can all agree that the safety of our children is a top priority. Whenever we have a situation where there are high volumes of children, the stakes get higher, as do the risks. With the hustle and bustle of the school environment – rushing to beat the bell, catching up with friends, balancing school books in one arm and sports equipment in the other – kids are distracted (not to mention cell phones!). When kids become distracted, the likelihood increases that they may make a misstep that puts them at risk of accident or injury. According to the Minnesota Department of Transportation (MnDOT), the top reasons for auto-related events involving children include:
- Running out from behind cars
- Crossing outside of designated crossing zones
- Child’s lack of understanding of traffic devices
MnDOT reports that crashes including pedestrians are eight times more likely to result in death than those not involving pedestrians. That likelihood is greatly impacted by the speed at which the car is traveling, as you can see from the figures below. Someone under the age of 30 years old only has a 3% chance of being killed by a vehicle traveling 20 mph, whereas it increases to 13% at 30 mph. The risk increases rapidly from, reaching about 52% when the vehicle speed is 45 mph. Slower vehicle speeds mean a pedestrian has a greater chance of survival if hit, which is an amazing benefit from a potential school speed zone.
When do we implement them?
MnDOT’s guidelines include three different components on studies related to school speed zone
1. Identify a school route plan. Our first thought when reviewing a school route plan should be How can we minimize conflict? We can do this by reducing the number of streets children need to cross to reach the school and ensure that the crossings have optimized visibility (e., removing shrubs and other obstacles that may affect visibility).
2. Identify the hazards around the school zone. There are nine criteria for evaluating hazards around the school zone:
- Roadway Geometry. How wide are the roads? Is there a shoulder? If there are curves, how wide is the road in the curve?
- Traffic Volume. Minimizing exposure to heavy volumes of traffic on the school route is preferable. If crossing on high traffic volume road is necessary, then we’ll need to consider using additional safety measures, such as crossing guards.
- Pedestrian Volume. In some ways, higher concentrations of pedestrians can be safer because drivers know to be on the lookout for pedestrians in heavily-traveled crosswalks or corridors. When pedestrian traffic is spread out in smaller volumes, the risk increases that a driver will be caught off-guard by a pedestrian on the road.
- Parking. On-street parking creates the risk of children darting out from between parked cars. We want to increase sightlines between pedestrians and drivers whenever possible, and on-street parking can be a big obstacle to that.
- Traffic Control Devices. Make sure that all traffic devices are up to standards and operational. In school zones, it’s important to consider the clarity of the instructions the device is providing because, as we’ve discussed, kids don’t always understand the meaning behind our traffic devices, signs, and striping. We want to eliminate confusion wherever possible.
- Sidewalks. Ensuring the maintenance and condition of sidewalks, including meeting ADA standards, in school routes is critical to making sure pedestrians use them properly.
- Fencing. Used properly, fencing can influence walking paths as well as separate children in areas such as playgrounds from busy roads.
- Crash History. Analyzing crash history can help to identify danger zones where the government agency or school can implement mitigation measures accordingly. If it’s not possible to mitigate the danger, it may be prudent to adjust the route to avoid these danger zones.
- Speed Zones. If other measures have been addressed and safe navigation still requires slower vehicle speeds, a school speed zone should be considered. MnDOT recommends lowering no more than 10-15 mph and adds to avoid arbitrary blanket values. Consider the surrounding characteristics as well as involve the local police for additional enforcement measures. We recommend checking the existing speed of traffic using tube counters to see whether people are complying with the existing speeds.
3. Education. Educating children via police liaisons, public works programs or education programs coordinated with the schools directly, will help to make sure they understand how to keep themselves safe while traveling near roadways.
Speed limit signs by themselves tend to be relatively ineffective. During our analysis, if we find that the 85th percentile speed is more than the speed limit, we like to recommend the use of flashing signage indicating school speed zones during the active school hours. Other measures include speed humps/raised pedestrian crossings, intersection or mid-block bump-outs, or using crossing guards to assist with safe crossings.
The unfortunate reality is there are an infinite number of ways that tragedy can strike when you combine vehicle traffic, particularly high-speed traffic, and high-volumes of young pedestrians. That’s why it’s incredibly important to control the speed and, whenever possible, the volume of traffic in school zones. By slowing drivers down and encouraging them to be aware of their surroundings, we give them more time to react to and avert a potentially dangerous situation.
Interested in learning more? Watch a recording of our Traffic Corner Tuesday webinar on School Speed Zones.
Great stuff! While I’ve seen many versions of charts showing fatality probability versus impact speed, I’ve never seen it broken out into age category. I think that helps to underscore some of the vulnerability issues we need to identify.
Data I’ve seen for fragility in car crashes (Leonard Evans’ book “Traffic Safety”) shows child categories, who like the elderly are more vulnerable to fatality. I suspect its the same for the fatality probability versus impact speed, but for the charts shown in your story I’m guessing the data is just not available.
Thanks for sharing!
Only thing this article didn’t include was the proper times to set a school speed zone
Assuming you are referring to the hour of day, the school speed limit can be applied differently depending upon the situation. Usually, we now see signs indicating the school speed limit is in effect whenever ‘children are present’. This catch-all applies during the school start and end times as well as events, lunch, or other times when kids may be outside around the school. It also avoids having the lower speed in effect during school holidays.
‘whenever children are present’ I have a question on this as I got a speeding ticket at 7:33 am. Children were not present and are not allowed at school until 7:50. The buses don’t get there until between 7:45 and 7:50. How could these ‘speed zones’ be in effect if no children were present?