Official: Full speed study may raise limit
undivided U.S. 183 as a divided four-lane road. Really divided, because in this case, the tollway will run down the middle.
Drive out there right now, and you’ll find two southbound lanes of U.S. 183, then a chasm with a nearly completed Texas 130 tollway, and two northbound lanes of U.S. 183 a couple of hundred feet off to the east. And those frontage roads are typical freeway width, 12 feet each, with ample shoulder lanes, 4 feet on the inside and 8 feet on the outside.
You’ll also find a 55 mph speed limit on those free lanes.
In other words, this much safer version of U.S. 183, where it is impossible to run into oncoming trafic, has a posted speed 10 mph slower than existed before. In fact, that same 65 mph speed limit still exists on the undivided, four-lane section of U.S. 183 north of the tollway. The trafic load, about 16,000 cars a day, is basically the same on both sections of road. And that northern section, with the higher speed limit, has more development along it than the divided section closer to Lockhart.
You might wonder how this can be. I’ll tell you.
When TxDOT builds a new highway, or radically changes an existing one (as happened here), it typically recommends a new speed limit to the Texas Transportation Commission, which then votes on that new limit. In this case, the commission — the same body that inked that long contract with the tollway company — set the 55 mph speed limit in late June.
Normally, TxDOT and the commission settle on a speed limit by conducting what is called a speed study, which uses radar to note the speed of at least 125 drivers during peak periods. Then the engineers figure out the speed that 85 percent of the drivers were at or below. The idea is that this is the fastest a prudent driver would go on the road at its most crowded times.
But what TxDOT has set for now is an “interim” speed limit for the period during and just after construction of the new road, according to Carol Rawson, who runs the agency’s Trafic Division. And for that, state law allows that limit to be based either on the state’s “prima facie” speed limit of 70 mph (the fallback speed for any Texas highway, in other words); the “design speed” of this particular road, which Rawson said is 60 mph; or a “trial run.”
TxDOT chose a trial run. Under this approach, a registered engineer drives the road at what seems to him or her a prudent speed, without looking at the speedometer, while a passenger notes how fast the car is going. Then the speed limit is set based on that. Really.
Sort of like a political poll where just one voter was surveyed.
During that trial run, the engineer drove between 46 mph and 56 mph. I was on that road three times in the past couple of weeks, and cars were going 60 to 70 mph. Even with the posted lower limit.
What makes this even more interesting is that the trial run occurred in April 2011, right in the middle of construction. I wasn’t there at the time, so I can’t say how many lanes were blocked or thinned by equipment or orange cones.
One more interesting element: The engineer was hired not by TxDOT, but by the SH 130 Concession Company. And according to Rawson, that outside engineer decided which of the three speed limits (70, 60 or 55) to recommend to the commission.
Which is where the tollway, and the number 85, comes in.
The Transportation Commission is expected to set the tollway speed limit at 85 mph, which a law passed in 2011 allows. It would be the highest speed limit in Texas, benefitting both the concession company (because a higher speed would draw more customers) and TxDOT (because the higher the speed limit, the more money the concession company pays TxDOT when the tollway opens).
A slower speed on the frontage road, of course, also benefits the concession company. Going 10 miles at 85 mph takes seven minutes. Slow down to 55, and it’ll take you 11 minutes. At 65 mph, it takes 9 minutes and 15 seconds.
Drivers no doubt won’t do that math. They’ll just know, I can go really fast if I pay a toll (about 15 cents a mile, an SH 130 company executive said last month), or I can go a pokey 55 mph for free. And the entity that will benefit the most from this disparity had a whole lot to do with determining its size.
Rawson emphasized to me the 55 mph is only the interim limit. She said a full-fledged speed study probably will be conducted about six months after the toll road opens, and a new limit could result from that.
But for half a year at least, commuters from Lockhart will have to deal with what seems to be an artificially low speed limit on a brand-new, straightas-a-string, very safe road. Some of them may get speeding tickets based on that lower limit.
And the tollway’s owners, along with TxDOT (which gets a small percentage of the toll revenue), will benefit.
Do you smell smoke?