Texas May Raise Speed Limit to 85 MPH

Speed limit increase may increase what Texas residents shell out for gas.

April 7, 2011, 11:35 AM

April 7, 2011— -- A bill to raise Texas highway speed limits to 85 mph could have motorists getting there faster but shelling out much more money at the gas pump.

Consumers will see an "increase in demand for petroleum because as we go faster our cars get a lot less fuel efficiency," says Patrick DeHaan, a senior petroleum analyst for GasBuddy.com, a gas price sharing website.

The bill, introduced by Texas Rep. Lois W. Kolkhort, would make the 85 mph limit the highest in the country, according to the Dallas Morning News. A similar plan is being considered by the state Senate, according to the AP.

But first the measure, which is part of a larger transportation bill, must pass engineering testing and other studies before the Texas Department of Transportation authorizes it.

"Though this bill has passed the House, it's still not law," says department of Transportation spokeswoman Kelli Petras. "Technically, we cannot talk about pending legislation. Once something is law, then we can look into what we need to do about it."

The Department of Transportation "would have to conduct extensive speed studies. We'd have to do engineering analysis before raising the speed limit on any roads in the state. That's our normal process. That will not change," says Petras.

"We are allowing a few ideas to continue: that is, the option to build designated truck lanes, and the option to build 85 mph lanes for passenger vehicles. Our state's Texas Transportation Commission would still need to approve this measure, only after a future highway was designed and built to handle the higher speeds or weights," Rep. Kolkhorst said in a statement to ABC News.

"With gas prices what they are, this would only be an option in the years ahead, and certainly only after a great deal of study. There's no highway in Texas today allowing for 85 mph, but we didn't to close the door on tomorrow."

Speed Limit Rising to 85 MPH Could Mean Pricier Daily Commute

In Texas, the impact on the wallet could be high for travelers as gas prices continue to rise. Residents paying an average of $3.60 a gallon might add an additional cost of 30 cents for the daily commute, since a higher speed limit could mean fewer miles per gallon.

For travelers on a lonely road, that gas usage could rise by double digits, depending on traveling methods. "We could be talking about increases of between 5 to 10 percent, depending on how much they drive," says DeHaan. And the effect will have a strong reach, he says, affecting every vehicle. "The cars that will be less impacted are newer vehicles that are geared for higher speeds."

In 2008, Edmunds.com, a website for automative consumers, did a fuel economy test that looked at speed and other factors to determine fuel efficiency. The test found that driving at a higher speeds decreased fuel economy from 12 percent to 30 percent, depending on speed and driving style.

The website wrote to readers: "If you are currently an aggressive driver (cruising speeds from 75-85 mph, constantly accelerating and changing lanes and braking sharply) and you decided to calm down (driving with the cruise control set to 65 mph), your fuel economy would improve an average of 35 percent. If you want to drive at higher speeds (77 mph with cruise control on) but you eliminate midrange acceleration, lane changes and harsh braking, your fuel economy will improve from 12.5 percent."

That's not good news for Texas. "The faster you go, the more fuel you're going to burn," says Dan Edmunds, director of vehicle testing at Edmunds.com.

And the miles per gallon data on the sticker of a new vehicle may not offer the best mileage rate for consumers able to put the pedal to the medal. "[Typically], the first highway mpg figure is based on the speed pattern of 65. It's a very complicated pattern that has been modified over the years to include higher speeds but nothing like 85 mph so there will definitely be more fuel burned at that speed, " says DeHaan.

Higher Speeds Mean Harder Work for Engine and More Fuel

Fuel consumption rises when driving in the fast lane because of airflow. "At higher speed limits there's more work for the engine to maintain that higher speed because by increasing the drag on the vehicle the amount of airflow pushing against the vehicle causes the engine to work harder," says DeHaan.

In addition to an uptick of gas prices, residents could see a rise in accidents. "Obviously, the two things that kill most people on our highways are speed and alcohol. Increasing it to 85, or even 75, will have a dramatic impact on the death and injury rate on those highways where it's implemented," Jerry Johns, a spokesman for the Southwestern Insurance Information Service, told The Associated Press.

Here's some good news: "No one has to drive the speed limit. They can always back down," says Edmunds.The Associated Press contributed to this story.