Crawling along Interstate 95 the other day in the usual bumper-to-bumper traffic, I snickered when I noticed the “speed limit 55” sign alongside the highway. We wish!
Of course, when the highway is not jammed, speeds are more like 70 mph, with the legal limit, unfortunately, rarely enforced. It got me thinking: Who sets speed limits on our highways and by what criteria?’
Why is the speed limit on I-95 in Fairfield County only 55 mph, but 65 mph east of New Haven? And why is the speed limit on I-84 just 55 mph from the New York border to Hartford, but 65 mph farther east in the “Quiet Corner?” Does the eastern half of the state get a break because nobody lives there?
Well, you can blame the Office of the State Traffic Administration (OSTA) in the state Department of Transportation for all the above. This body regulates everything from speed limits to traffic signals, working with local traffic authorities (usually local police departments, mayors or boards of selectmen).
OSTA is also responsible for traffic rules for trucks (usually lower speed limits), including banning them from the left lane on I-95 in most places.
Congress dropped the interstate speed limit to 55 mph in 1973 during the oil crisis, then raised it to 65 mph in 1987 and repealed the federal speed limit altogether in 1995 (followed by a 21 percent increase in fatal crashes nationwide), leaving it to each state to decide what’s best.
That means 75 mph in Arizona and Texas, while some Utah roads permit 80 mph. Trust me, after recently driving more than 1,000 miles in remote stretches of Utah, things happen very quickly when you’re doing 80-plus mph. Fast means dangerous.
Driving too slow can also get you in trouble as many states now ticket drivers who are slowing traffic in the left lane.
About half of Germany’s famed Autobahns have speed limits of 100 km/hr (62 mph), but speed is discretionary outside the cities. A minimum of 130 km/hr (81 mph) is generally the rule, but top speed can often be 200 km/hr (120 mph).
Mind you, the Autobahn is a superbly maintained road system without the bone-rattling potholes and divots we enjoy on our highways. The German-built Mercedes and Audis on these roads are certainly engineered for such speed.
American cars are designed more for fuel efficiency than speed. Best gas mileage is achieved by driving in the 55 to 60 mph range. Speed up to 65 mph and your engine runs 8 percent less efficient. At 70 mph, the loss is 17 percent. That adds up to more money spent on gasoline and increased environmental pollution, all to save a few minutes of driving time.
But aerodynamic drag — eating up to 40 percent of total fuel consumption — is an even bigger factor to losing fuel efficiency. Lugging bulky roof-top cargo boxes worsens fuel economy by 25 percent at interstate speeds. So does carrying junk in your trunk (or a lot of passengers): a 1 percent penalty for every 100 pounds.
Even with cheaper gasoline, it all adds up — at any speed.
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Jim Cameron on Highways
- Looking to Save the State Money? Stop Spending on Sound Barriers: Cameron on Transportation (Jan. 27)
- How a 10% ConnDOT Cut Would Affect Connecticut: Cameron on Transportation (Jan. 20)
- Predictions for Planes, Trains & Automobile Traffic in 2017: Cameron on Transportation (Jan. 14)
- Don’t Blame the Trucks for I-95 Congestion: Cameron on Transportation (Nov. 12, 2016)
Jim Cameron has been a Darien resident for 25 years. He is the founder of the Commuter Action Group and also serves on the Darien RTM and as program director for Darien TV79. The opinions expressed in this column are only his own. You can reach him at CommuterActionGroup@gmail.com
Republished with permission of Hearst CT Media.