DALLAS TX:ETX now – thanks to dumpster demolition

The Dallas North Tollway got four electronic toll express (ETX) lanes April 21, a couple of days after a contract was signed. Gulf Engineers Corp started the work within hours of a spectacular smash Jan 30 in which a dumpster-hauler took out a toll island, toll booth, ramparts and canopy stanchions between two ET-only lanes at the Number One mainline plaza toward the southern end of the tollroad at Wycliff Av. They had been working on another toll plaza job and were immediately engaged to make the crash site safe and clean up debris. Later that day officials of the North Texas Tollway Authority (NTTA) decided that rather than rebuild the toll lanes in lane-constrained fashion, they would advance by two years plans to convert to multi-lane open road electronic tolling.

NTTA engineers worked evenings and weekends to turn out working drawings for sign/ET-gear trusses, a new plaza pavement striping plan, the layout of vehicle classification ‘smart loops’ and the detail of curbs and jersey barrier separations. A video enforcement system that had also been in the works was also implemented for the first time on the new ETX lanes.

During the course of the job NTTA decided to centralize lane controllers. They built an outbuilding on the far side of the plaza and all the ETX controllers are there, so technicians can work from one point. Other lane controllers will be moved there when the rest of the plaza is modernized.

The express lanes are pairs of standard 3.65m (12') lanes and with offsets either side there is 8.2m to 9.2m (27' to 30') pavement jersey barrier to jersey barrier. The jersey barrier separating the express lanes from the stop-to-pay lanes presently extends about 60m downstream and upstream. It consists of 7ton 9.2m (30') lengths of precast jersey-profile barrier joined by angle iron and bolted into the pavement. Engineering director Mark Bouma says that’s so they can readily extend the barrier or shorten it to take traffic behavior into account. Already they see the need to modify some pavement striping to improve traffic segregation.

The new ETX lanes will not be posted for full highway speed. When we inquired no decision had been made but 35mph and 45mph postings were being discussed. But speed enforcement is pretty casual everywhere in Texas.

The ETX lanes ‘read’ clearly to motorists. They have huge black ‘T’s (for Toll Tag the local name for ET) on a bright orange circular background as signage and the gantry over the ETX lanes is more open and higher than the canopy over the adjacent stop-&-pay toll lanes.

The contractor worked on a Texan handshake until a few days before the project was finished when the paperwork caught up with the job – a procurement procedure that would be difficult at most state DOTs!

Estimated cost of the project to date is about $1.1m, a fraction of what is being quoted for ETX lane conversion projects in the northeast and midwest. (see GSP!)

Repeating the crash-expressification

The toll agency won plaudits from motorists for the eleven-and-a-half week (80 day) job. But, as they say, no good deed goes unpunished. Now the pressure is on NTTA to repeat the ‘expressification’ of electronic tolling elsewhere.

Mark Bouma, director of engineering says: “This one was a winner, and it has raised expectations.”

The board has asked the staff to advance installation of express toll lanes at the next major chokepoint on the Dallas North at the #2 or Keller Spings mainline plaza near the midpoint of the tollroad. This is the most heavily trafficked and most congested toll plaza in the NTTA system. It handles 150k veh/day through 12 toll lanes. Plaza#1 just completed carries about 100k veh/day and normally has 15 toll lanes. During the recent construction 4-lanes were totally out of action for the duration of the smash and the construction work. 11 toll lanes handled the 100k veh/day without too serious backups except during the peak of the peak.

But Plaza#2 will be a different matter, Bouma says. Work is already under way on 2 extra toll lanes which will bring the total to 14, before work begins on the ETX. Even so with 150k veh/day they cannot take toll lanes out for the duration. Work will have to be done at night and weekends with lanes returned to traffic weekdays daytime. Bouma says the most difficult part of ET-expressification will be the new pavement in the ETX lanes. NTTA uses Peek ‘smart loops’ for vehicle detection and axle counting. They need to be installed in sawcuts in new continuous reinforced concrete 30m long x18m wide x250mm deep (100’x60’x10") in a single pour, a bit like a bridge deck job.

The challenge will be to have work going on around the clock perhaps over a long weekend. There would be an intensive job with several concrete breakers and loaders first to remove the existing pavement. Reinforcement could be pre-assembled in massive grids offsite and trucked in. Then quickcure concrete would need to be poured. Most of the other work could be done nights: toll booth removal, island and rampart demolition, canopy removal, gantry installation, signage and equipment mounting, striping, jersey barrier, and so forth.

The details are going to be hashed out at design and construction sessions this month for presentation to the board in June. (Mark Bouma NTTA 214 461 2058 mbouma@ntta.org)

MISTAKE: Only mis-step made by NTTA was the claim in an April 20 press release that NTTA’s tollroads “are the only tollroads in the country offering this unique configuration.” Way out.

Multi-lane open road electronic tolling or ETX was pioneered by the E-470 in Denver Colorado at its first mainline toll plaza opening July 15, 1991, soon followed by the Kilpatrick, Cherokee and Chicasaw tollroads in Oklahoma September 1, 1991. Others to have ETX designed into new facilities in the following years were Georgia 400 in Atlanta, all four plazas in the Foothill, San Joaquin and Eastern tollroads in Southern California, Western Expressway (FL-429) in Orlando FL, Biddles Corner plaza on DE-1, the Toronto 407-ETR, and Melbourne Australia City Link non-stop automated toll roads, 91 Express Lanes and I-15 HOT lanes and I-10 and US-290 HOT lanes in Houston. Retrofit of ETX into existing toll plazas is more difficult but - listen up Dallas – was pioneeed by those Harris County guys down by the Gulf, all nine mainline plazas in the Houston TX system, four plazas in Chicago on the Illinois Tollway system, and the Pearl Harbor spur near the Delaware River on the NJ Turnpike. The PGB and now Dallas North are following a well-established path laid down by others. None so far as we know has done as quick a job, or as economical a job, as NTTA did on the Dallas North at Plaza#1.