The Priceonomics website looks at the work being done by Lieutenant Gary Megge of the Michigan State Police, who has been steadily increasing the speed limit on "nearly 400 of Michigan’s roadways." And while some people do complain about the increases, Lt. Megge believes that raising speed limits make the roads safer.
This “nationally recognized method” of setting the speed limit as the 85th percentile speed is essentially traffic engineering 101. It’s also a bit perplexing to those unfamiliar with the concept. Shouldn’t everyone drive at or below the speed limit? And if a driver’s speed is dictated by the speed limit, how can you decide whether or not to change that limit based on the speed of traffic?
The answer lies in realizing that the speed limit really is just a number on a sign, and it has very little influence on how fast people drive. “Over the years, I’ve done many follow up studies after we raise or lower a speed limit,” Megge tells us. “Almost every time, the 85th percentile speed doesn’t change, or if it does, it’s by about 2 or 3 mph.”
As most honest drivers would probably concede, this means that if the speed limit on a highway decreases from 65 mph to 55 mph, most drivers will not drive 10 mph slower. But for the majority of drivers, the opposite is also true. If a survey team increases the speed limit by 10 mph, the speed of traffic will not shoot up 10 mph. It will stay around the same. Years of observing traffic has shown engineers that as long as a cop car is not in sight, most people simply drive at whatever speed they like.
|Crowsflight: a GPS App That Just Points to Your Destination|
|All the Technology of a High-End Car, Inside a Motorcycle Helmet|
|Mini-Documentary on Those Who Will Be Taking a One-Way Trip to Mars|
|Why Does it Take so Long to Mend an Escalator?|
|Urban Exploration: London's Post Office Railway|
|“A novel experiment by a government to work with journalists and educators to combat the spread of online misinformation.”|
|“The race is on to create lab-grown meat products.”|
|“Google Owns 28% of Your Brain.”|
|CaptchaTweet: Write Tweets in Captcha Form|
|The (Very Scary) People of Public Transit|
|“We’ve received requests to add some artificial noise to the buses so that people can hear them.”|
|How to Avoid Jury Duty|
|“Initial riders may be more comfortable getting into a car with a human in the driver seat.”|
|“When Life Gives You Lemons.”|
|“Both spacecraft are still operational when they reached interstellar space.”|
|Bird Shit Advertising|