Ten Tired Traffic Myths

According to City Lab, here are some traffic myths that just refuse to die.

1. The most enduring popular traffic myth holds that building more roads always leads to less congestion. Instead it causes induced demand so that that building more road eventually (if not always immediately) leads to more traffic, not less.

2. More transit means less traffic can also be a myth.  Studies have shown that over the long-term, transit doesn’t decrease traffic.  However, transit does offer other benefits better quality of life to more economic might, and transit must still be part of any solution to traffic woes.

3. One enduring myth holds that converting general road space into a bike lane is bad for traffic. But when bike lanes are well-designed, that’s just not the case. New York City proved as much with bike lanes recently installed on Columbus and Eighth avenues. By reducing the width of car lanes from 12 to 10 feet and adding protected left turns, the city was able to preserve vehicle volume and actually reduce travel times by 35 and 14 percent, respectively.

4. It is commonly believed that wider lanes are a safer design since they give drivers a bit more room to maneuver. But what some new research published in 2015 showed quite clearly was that wider lanes also invite cars to drive faster—erasing whatever safety benefits might be gained by additional space, and actually leading to more dangerous streets.

5. On average, drivers change lanes every 1.25 miles. While it might seem like the next lane over on the highway is always moving faster, the truth is that’s usually not the case.

6. Traffic is not caused by the other guy, that jerk in the sports car car cutting people off or the lady constantly tapping on her brakes. It’s everyone’s inability to hold a steady speed and following distance that causes backups.

7. You actually don’t need to have a lot of cars leave the roads, as many believe, to affect traffic. Traffic is non-linear so if you remove just 1 percent of commuters off the rush-hour road in especially high-traffic corridors, as some work has shown, you can reduce travel times by 18 percent. (Just think about how light traffic is in August even though only some people are on vacation.)

8. Removing roads won’t necessarily causes nightmarish traffic. Drivers adapt extremely quickly to changes to the road network—a phenomenon that experts refer to as “disappearing traffic.” Some people shift their routes, travel times, or modes when an existing road closes; others simply decide not to make a trip at all. As the authors of one study put it, “predictions of traffic problems are often unnecessarily alarmist.”

9. Cheap gas isn’t all good, it turns out. It’s bad for all the hidden social costs of driving, which have been estimated at some $3.3 trillion a year. Of that total, at least $1 trillion represents time lost to congestion both at home and at work.

10. Gas taxes don’t cover the costs of roads, although most believe they do. In its early days, back in the 1960s, this road user fee did handle the vast majority of maintenance expenses. But since that time its powers have steadily eroded, with Americans now paying some of the lowest gas taxes in the world. We now have a significant infrastructure maintenance crisis with little end in sight.