Speed limits rising

Moderated by Tom Sabulis

The Georgia Department of Transportation is looking at raising the limit from 55 to 65 on I-285. In Texas, the nation’s first 85 mph speed limit is planned for a 41-mile toll road between Austin and San Antonio. A local policy analyst argues that increased speed doesn’t necessarily mean more accidents and fatalities. A national safety expert says drivers automatically go over current limits and the statistics don’t bode well for healthy travel at higher speeds.

Commenting is open below Adrian Lund’s column.

By Benita M. Dodd

Most Georgians who travel the long, watch-paint-dry stretch that is I-16 between Savannah and Macon understand the unwritten rule:

You may exceed the posted speed limit of 70 mph, but not by more than 9 mph. If law enforcement clocks you at 80 mph or over, you’re toast.

In Texas, transportation officials acknowledge this reality and want to profit from it. In their case, they’re not just seeking revenue from speeding tickets, like most other jurisdictions.

They plan to implement the nation’s first 85-mph speed limit on a stretch of toll road in return for $100 million from the private toll operator.

The plan, for about half of a 91-mile toll road between Austin and San Antonio, is by no means outrageous or a harbinger of safety problems:

  • Some rural roads in Texas and Utah already permit speeds up to 80 mph. A Utah Highway Patrol spokesman warned that people who thought they were safe in the 10 mph-or-less window would find less leniency for exceeding the speed limit.
  • More than half the German Autobahn’s 8,000-mile network has no posted speed; the average speed is 84 mph.
  • Australia’s “autobahn” was Stuart Highway, a 1,761-mile stretch where an 80-mph speed limit was implemented in 2007. Just this month, Northern Territory leaders expressed support for once again eliminating the limit, pointing out that 44 people died on the territory’s roads in 2006 but more than 50 were killed in 2007 — after the speed limit was introduced.

The United States saw a 22.1 percent decline in traffic fatalities from 2001 to 2010, according to the Annual Road Safety Report 2011 produced by the International Transport Forum.

Forty-eight percent of those fatalities took place on highways outside urban areas, despite higher population concentrations in urban areas.

Yes, higher speed limits are often allowed in rural areas, but it’s tough to determine how many fatalities would have been avoided if the speed was lower, drivers were less tired on long roads or trauma care facilities were nearer.

The speed differential — the difference between the speed of vehicles continuing along a main roadway versus those that are entering and exiting the road — is not as great a concern on a well-kept, limited-access toll road that has few entry and exit points.

The private operator is betting that when the toll road opens in November, the higher speed will draw more customers looking for a quicker, faster drive and willing to pay extra for a congestion-free trip.

It’s a safe bet.

It’s also planning ahead: “Smart” cars that can automatically keep a safe distance from other vehicles — and can even operate driverless — already promise to be the wave of the future.

They increase lane capacity, improve traffic flow, set higher safety benchmarks and avoid human error.

Google recently announced that its driverless cars had traveled 300,000 miles without incident.

Of course, some Texans may think officials appeared to “game the system” by deciding to simultaneously reduce the existing speed of the adjacent “free” frontage road.

Benita M. Dodd is Vice President at the Georgia Public Policy Foundation.

By Adrian Lund

Imagine cruising down the highway at 85 mph without getting so much as a raised eyebrow, let alone a ticket.

For many drivers, it sounds like a dream, and it’s set to come true on one Texas road.

But we’ve seen this one before, and it doesn’t end well.

Decades of research show that when speed limits are raised, drivers go faster and more people die in crashes.

The Texas Transportation Commission’s decision to establish the highest speed limit in the land on a new toll road between Austin and San Antonio means drivers there will be able to get to their destinations quickly, but at a cost.

High speeds increase the likelihood of a crash while simultaneously slashing the odds of surviving one.

Crashes are more likely because, at a higher speed, a vehicle travels a longer distance in the split second it takes to react to an emergency.

And the faster the vehicle is going, the further it will travel before coming to a stop after the driver slams on the brakes.

When crashes occur, they are deadlier at high speeds because the energy involved increases exponentially as speed rises.

At the Insurance Institute for Highway Safety, before we rate a vehicle for frontal crash-worthiness, we send it hurtling toward a barrier at 40 mph, resulting in a severe collision.

Most new vehicles today do well in our moderate frontal overlap test, meaning people could survive a similar real-world crash without serious injuries.

But at high speeds, all bets are off.

The vehicle’s structure won’t hold up, and airbags and safety belts won’t be able to do their job. When a crash is imminent, a car traveling 65 mph has a much better chance of getting down to a survivable speed before impact than a car traveling 85 mph.

We know that many drivers exceed posted limits, but that doesn’t mean they don’t take them into account.

Drivers typically pick a speed at which they think they won’t get a ticket — often 5 to 10 mph over the limit.

Many Texas drivers are no doubt already used to driving 85 mph on roads with 75 or 80 mph limits.

They’ll read the 85 mph signs as license to go 90 or more.

The 17 years since Congress did away with the national 55-mph maximum speed limit have given us plenty of opportunities to see what happens when speed limits are raised.

After the speed limit on three urban freeways in Texas was raised from 55 to 70 in the mid-1990s, we found that half the vehicles were going faster than 70 within a year, compared with 15 percent before.

Seventeen percent were exceeding 75 mph, compared with 4 percent before the change.

Around the country, such increases translated into more deaths. In 24 states that raised speed limits, including Georgia, we found 15 percent more fatalities on interstates and freeways than otherwise would have been expected.

Even with today’s speed limits, speed-related crashes cause more than 10,000 deaths a year — nearly a third of all crash fatalities in the country.

States could prevent some of these deaths if, instead of giving drivers permission to go ever faster, they vigorously enforced existing limits to slow drivers down.

Adrian Lund is president of the Insurance Institute of Highway Safety.

33 comments Add your comment


September 19th, 2012
2:38 pm

I have been driving all across the US for close to 35 years now. Even back during the NMSL (55 maximum) everyone drove 65 – ~70-75 mph. I well remember the time before this when many western states had no numerical speed limit.

I drove regularly in Montana in the late 90s when there was no posted limit ( Reasonable & Prudent during daylight hours was the law/ 65 mph night). In Montana on two lane roads during this time speeds topped out around 75 mph and around 85-90 mph on freeways. I would drive for 10 hours @ ~90 mph on interstates across the state, a good felling I will never forget!!!

In the most of the rest of the west today including Montana the allowed limit is 80 to 85-90 mph depending on weather conditions. Today you can cross many of these states with the cruise set at 84-85 mph without worry of a ticket as long as you follow the real safety related enforced rules of the road. In these places you will get pulled over and charged with aggressive driving ticket $$$$ in a second for doing any of the following: Following Too Close, Failing to Signal for lane changes @ speed, and a real biggie is Blocking The Passing Lanes.

In flat empty straight as an arrow rural GA there is no reason for the limit to be kept @ the low political limits posted today. Most of the interstates and four lane highways across the state could easily safely support 75-85 posted limits, from travels across the state these are the safely traveled speeds today. For limits to have any relevance they must be based on real world 85th percentile speeds, 70+ years of DOT date proves this. Over the last few years posted limits across the US have been rising and every year without exception the death rate per miles traveled has continued to dropped to lowest level in the history of driving!!! Next time some idiot quotes that tired old line of speed kills, ask them if so how is the above quoted fact possible????

Today anywhere and everywhere across the US north south east & west with no regard to the under posted political maximums on two lane roads 65-75 mph and on rural freeways 75-90 mph is the real limit today. Drivers going with the flow are not the danger but drivers doing things that impede flow are.

And on drivers just going faster if the limit is raised western states have document the opposite. What they have found is that when the limit is raised to close the actual 85th percentile speed travel average speeds drop. Drivers will only drive as fast or as slow as they feel safe and comfortable with no regard to what arbitrary numbers are painted on a sign!! If they were to post 70 on the signs on I-285 flow speed would actually drop not increase, Colorado DOT, CAL DOT, Utah DOT just to name a few have the documented data to prove this is what would happen.


September 19th, 2012
1:33 pm

@Rickster and Mangler

It’s about 150 miles from Macon to Savannah on I-16. At 50 mph, that’s 3 hours. At 75 mph, that’s 2 hours, and at 100 mph, that’s 1.5 hours. If you can’t do the math in your head, use a calculator. The formula is D = RT.

Not two minutes…


September 19th, 2012
1:29 pm

Besides, speed limits, like red light cameras, are just another means for the state and the county to steal money from folks. See the stupid super-speeder law. I’m not a super-speeder until I go 75 on a 2 lane road (which could be up to 40 over the speed limit), but I’m a super-speeder at 85 on I-16? What’s with that?

Who came up with this lame brain idea? And dear old Sonny said, when he signed the bill, how much this new law will increase revenue for the state.