Roughly 70 people attended a traffic calming presentation led by national expert Ian Lockwood Monday afternoon.

“Traffic calming is taking the mean fast cars and getting them to be slow, happy cars,” joked Lockwood.

On a more serious note, Lockwood said that with slower driving speeds kill rates decrease for pedestrians and property damage decreases as well should there be an accident.

Traffic Control

There are four traffic control devices: traffic calming, street scaping, route modification, and traffic control.

Lockwood took the audience through defining two types of streets: framework and non-framework streets. The former go someplace and have emergency vehicle responsibility. All other streets are access oriented (to homes, businesses). Whether a street is a framework or non-framework street dictates what kind of traffic calming a community can use.

Lockwood noted that speed humps are much more effective to slow traffic than speed bumps. Humps have a twelve to fourteen foot width, which tricks an automobile's suspension into thinking it is going up a hill. A bump on the other hand is seen more in parking lots. They have shorter widths and are raised higher off the ground.

“When you are calming a neighborhood, it is also a good idea to alert drivers that they are entering a calm area,” Lockwood said.

He said that planting trees along the width of a street actually works to create a sense of enclosure which affects a driver's sense of perception and works to calm traffic.

Valley gutters place on roadsides can be used to limit the perceived width of a street. This prevents a driver from feeling they are on a “runway” and thus driving faster.

As Lockwood proceeded through his photos of numerous projects he has worked on, there were audible gasps and “Oohs” as he would show before and then after photos.

Roundabouts

When Lockwood moved onto roundabouts he noted that in a standard four way intersection there are 32 vehicle-to-vehicle conflict points. Meaning there are 32 points in the intersection where vehicles can crash into other vehicles. There are also 24 vehicle-to-pedestrian conflict points.

Lockwood contrasted this with roundabouts which only have 8 vehicle-to-vehicle conflict points and 8 vehicle-to-pedestrian conflict points.

Roundabouts have special pedestrian crossings, with split islands (crossing one part of the street, and then the other) whereas traffic circles have normal crossings. Traffic circles, Lockwood said, can be very dangerous as cars still travel at high rates of speeds.

Roundabouts can tend to be more efficient, Lockwood said. Which allows communities to use extra space that was once devoted to turn lanes to use the land in other ways that can increase business/economic opportunities.

While roundabouts are efficient, they are not for every intersection Lockwood cautioned. “We are not roundabout zealots,” he said. Study and testing are necessary, despite the versatile efficiency that roundabouts can offer.

Something that you will see in the future (five to ten years), Lockwood said, is shared spaces. These are streets where drivers, pedestrians, shopping, bikers all share the space. While they look chaotic, Lockwood said, the safety record is impressive and accidents tend to go away in shared spaces because people traveling in a variety of forms are able to do so in an equitable manner.

They have the effect of putting the responsibility back on the driver, as opposed to signals, signage, etc.

“When you put your car in drive and your head in neutral,” Lockwood said that is when crashes tend to happen.

Why do cities exist?

Lockwood explored the idea of cities and their function.

Cities exist to bring people together for efficient exchange, he said. Cities exist to minimize travel. To accomplish this there is an emphasis on access (driveways, parking, throughways)

But, the past twenty years there has been a focus on mobility (moving traffic with speed). Ultimately, these types of plans defeat the idea of cities because they spread cities out and increase travel time. As examples of this, Lockwood cited Houston and Phoenix.

Michigan Department of Transportation

Also on hand was Brian Chomas,  from MDOT.

In 2001, Chomas said, there were only a handful of roundabouts in the entire state. By 2008, however, with heightened interest, usage has increased.

Chomas stressed the importance of correct design and keeping the design simple.

He presented a variety of videos on how to drive in roundabouts currently in use in Michigan.

So what about Pedestrians?

“I am a cyclist myself,” said Lockwood, “and in some areas roundabouts are applicable.” In an example from Clearwater, MI Lockwood pointed out that since that time not one pedestrian has been injured.

Lockwood said that the data clearly shows how the injury rates at roundabouts compared to traffic signals are significantly lower. He also said that people will speed up to make it through a green light, but drivers do not speed up to get to the roundabouts because there is not a light “to beat.”

And it is in that speeding up to get through the light that crashes between vehicles and pedestrians occur.

We need to shatter this myth about pedestrian safety at roundabouts said Lockwood. Even the insurance industries in North America support installation of roundabouts he said because it saves them money.

You see across North America, Lockwood said, that based on data from this continent that the insurance companies, Federal Highway Administration, and State Department of Transportations across the continent are installing them as options that are more safe.

But it is important not to pan what is working in so many different communities across this country, Lockwood said, just because your community may not be ready for it.

The closest two roundabouts I have seen were about six feet apart Lockwood said. There is an interest to keep them a fair distance away from traffic signals intersections, because roundabouts will outperform the traffic signal intersections. Lockwood said it might be a good idea to start with a roundabout in a non-intensive section before committing to high traffic density area. That way the community has the chance to adjust.

If you want to learn more you can download the Smart Transportation Guidebook from www.smart-transportation.com

Also, MDOT has a channel on YouTube with instructions on how to drive in a roundabout. Or, head to their website at http://www.michigan.gov/mdot/roundabouts.