One of the more interesting talks given at the American Dream Coalition Conference in Atlanta concerned the effect of traffic calming devices on emergency response teams. Les Bunte Director of the Emergency Services Training Institute at Texas A&M detailed the time lost by emergency response teams because of traffic calming provisions.

These response times are important because every minute delay for someone suffering a sudden cardiac arrest (SCA) results in the loss of life for a given number of people. The longer the delay the more people that will die, for each minute of delay survival rates drop 7 to 10 percent. The difference between 6 minutes and 7 minutes are survival rates of 45 percent and 30 percent respectively. After 10 minutes the survival rate is less than 5 percent.

The increased response time depends upon the type of traffic calming device. Speed bumps typically add somewhere between 30 and 45 seconds to response time. Three speed bumps can add over 2 minutes to response time. This equates to several lives. Police cars tend to speed over speed bumps and worry about the damage later. Ambulances and fire trucks cannot to that and must traverse speed bumps carefully.  

One thing that isn’t immediately obvious but makes perfect sense upon reflection is the care with which ambulance drivers must cross speed bumps when carrying injured patients. This extends travel time to the hospital which may be crucial in certain cases. Severely injured patients, especially spinal injures, can suffer further injury even carefully crossing a speed bump.

Another problem is that traffic calming devices are not always clearly visible at night. Fire engines have sustained substantial damage by racing to a fire and not seeing the speed bumps in time. There have been cases where roundabouts, another typical traffic calming device, literally could not accommodate the larger fire trucks like a hook-and-ladder. Even if they could the time lost in negotiating roundabouts could be the difference between saving and not saving a house.

Another peculiarity that Bunte pointed out was that traffic calming efforts were rarely constructed where there is a statistical demonstrated for the need. What this translates to is that most pedestrian fatalities are on major roadways while most traffic calming devices are placed in neighborhood areas where few fatalities occur. In other words, they are mostly a wasted effort.

Traffic calming devices also increase pollution and vehicle emissions while slowing emergency response times, all detrimental to health. What looks like a good idea at the outset has all these unintended consequences that would have been obvious had the planners just thought about it a little more.

Director Bunte wrapped up by saying we need to look at the real value of traffic calming versus actual delay in emergency response times. The reality may be that more lives are being lost because of increased response times to emergencies than are being protected by traffic calming devices. This may be a counterintuitive conclusion but according to Bunte is actually the case in many cities, maybe even ours.    

Don Newman, senior policy analyst for the Grassroot Institute of Hawaii can be reached at: mailto:don@grassrootinstitute.org