DALLAS TX:Toll booth crash accelerates ETX

A serious truck hit on the Dallas North Tollway’s Wycliff Plaza (#1) has led the North Texas Tollway Authority (NTTA) to move forward by two years plans for electronic toll express (ETX) lanes. Rather than rebuild the damaged section of the toll plaza, NTTA officials decided to close off the debris-filled lanes and to engage a contractor to implement full highway speed open-road electronic toll (ET) lanes now. The work is being done on a time and materials contract, and is expected to take 8 to 10 weeks.

Dumpster hits and dumps

Just after noon on Jan 30, a truck carrying a full load of construction debris in a haul-on dumpster travelling southbound smashed into the gore and toll booth between toll lanes 7 and 8, demolishing much of the concrete ramparts, crushing the toll booth, destroying a lane controller, tearing away the canopy posts, bringing down canopy equipment, and severing wiring to about two-thirds of the 15-lane toll plaza. The truck equipped with an electronic toll (ET) tag was heading for one of two ET-only lanes – probably lane 8 – at about 75km/hr (45mph) but apparently the load had shifted on the truck and caused the driver to lose control of his rig and to hit the structures between the toll lanes. The truck had sufficient momentum to break up the reinforced concrete island ramparts, take away the toll booth and substantial canopy posts much of which collapsed in front of and on top of the truck which continued some 20m (70') beyond the toll lanes.

Witnesses said that the truck had been swerving as it approached the toll plaza, apparently from the dumpster moving in its frame. It went through the toll island and booth with an enormous roar and as it came to a halt there was a second roar as the improperly attached dumpster came completely loose and rolled off the chassis of its tractor and ended up on its side on the pavement of the merge area alongsided the wrecked tractor and amid the toll plaza island debris it had created.

The driver was well protected in his cab and only sustained minor injuries, and no one else was hurt. The driver’s name is James Griffin, which generated merriment at NTTA because that is the same name as the Texas Turnpike Authority’s famous engineer and former executive-director who is still active and wellknown in Texas toll circles. Perhaps they should rename it the James Griffin Toll Plaza when it opens with ETX?

Plaza #1 near the south end of the Dallas North Tollway (DNT) was built as part of the original section of the tollway in 1967-8 with toll booths at which vehicles stopped to pay the toll to a toll attendant. The toll lanes are just 3m (10') curb to curb between the islands - which was a rather conventional compromise between the need to provide just enough clearance for wide vehicles while encouraging narrower vehicles to drive within arm-reaching distance of the toll collector in the toll booth.

As in most established toll facilities electronic tolling has been ‘retrofitted’ into former conventional toll lanes, so the islands and toll booths were left as-built. The ET-only lanes are signed for 10mph because of the relative narrowness of the lanes, but the NTTA has made no effort to enforce the speed limits. NTTA officials say the traffic generally goes through plazas#1 and the same-era plaza#2 at 30 to 40mph. (Plaza#3 a newer one with a tunnelway for toll collectors has ET-only lanes posted at 30mph)

They estimate Griffin in his dumpster-hauler was ‘speeding’ in the sense of going somewhat faster than average traffic, but not a great deal faster.

Texas seems even laxer than the rest of the country in speed enforcement. We noticed in uncongested conditions Dallas traffic generally flows at 70 to 75mph on urban motorways posted for 55mph, whereas we Marylanders try and keep to the 65 to 70mph range with similar speed postings.

World speed record in ET-only lane?

NTTA has no grade separated walkway at Plaza#1 or #2, the original toll plazas of the DNT. Because of the dangers to toll collectors crossing ET-only lanes, collectors working the toll booths remote from the plaza building have to use an NTTA shuttle van which goes via the closest interchange bridge to get back and forth. A temporary portable toilet has been located on the far side so they can’t use “needed to pee” as an excuse for crossing the lanes. Collectors who break the no-crossing ET-lanes rule face dismissal. One collector was dismissed for the offense, so there has been no bluff there.

NTTA officials think motorist speed enforcement is a lost cause in the Texas environment. (This IS the wild west, land of red meat, and big boots, remember!)

They claim a possible world speed record for a pass through a single retrofitted ET-only toll lane. 136mph (219km/hr) was recorded by their lane equipment. It was a motorcycle, they hasten to add by way of reassurance. There was more clearance than a car. But in five minutes of watching traffic at the retrofitted ET-only lanes we noticed a number of vehicles barely slowing to 50 to 60mph, while most traveled through at perhaps 30 to 40mph with just a few dropping to say 20mph. We saw none close to the posted 10mph.

Despite this there have been no previous smashes in nearly eleven years of ET at the Dallas North Tollway, which was the pioneer of the technology in the US. Moreover the whole marketing of ET emphasizes time savings and speed. NTTA ads for their ‘TollTag’ as they call their ET show a vehicle with speed streaks in its wake (see above.) So it would go counter to the whole culture of the technology and to its natural sales pitch then to be chiding motorists to “go slow.”

James Griffin, the demolisher, has not been charged with speeding but NTTA lawyers are talking with his company’s insurance people about a financial settlement. They are seeking compensation for the damage done to equipment and structures, cleanup costs and toll revenues lost. NTTA maintenance crews and a contractor cleared the debris within hours and ten toll lanes out of fifteen were open again for the evening peak. But a lot of those motorists with ET-tags got free rides because cabling to antennas and lane controllers in the far lanes had been severed. Although the canopy over the crash site remained – engineering director Mark Bouma quips it was held up “by habit” rather than any structure he could explain – it was sagging ominously. The quick-deployed contractor installed jacks under the canopy to keep it in place until it could be systematically cut and demolished a few days later. All toll systems were restored by the next morning with temporary cabling.

However traffic was down for several days because of news of the smash and the closure of toll lanes. The #1 plaza runs about 95k transactions/day, and further north the similarly configured #2 plaza at Arapaho runs around 130k tolls/day. NTTA plans were to rejig #2 for 2x2 ETX lanes in 2002 with #1 plaza following in 2003. Now plaza#1 will be done in two stages, the first going on now to provide the basics of ETX. In a second stage the rather daggy rustic canopy will be removed and replaced with one providing new signage and an elevated walkway for collectors to cross safely. It will also provide for ET equipment and enforcement cameras to be adjusted from above. NTTA officials say they were impressed by the OOCEA’s Western Expressway mainline plaza overbridge and plan to adopt some of its features. The OOCEA design is built around a longspan truss which avoids the need for intermediate posts - a big advantage if assaulted by an errant truck with a dumpster!

The decisive decision

Rick Herrington, information technology (IT) director and Mark Bouma, head of engineering were on the scene within an hour of the Jan 30 crash, and were soon joined by executive-director Jerry Hiebert and other senior NTTA staff. Herrington and Bouma had been working on “a very preliminary concept” for conversion of the plaza to electronic toll express lanes in 2003 in the weeks before. They also had some drawings of a new signage scheme for attachment to the canopy, so their minds were on future improvements.

Herrington says that as soon as he arrived on the smash scene and saw the seriousness of the damage at the toll plaza, he thought to himself: “Perhaps we don’t need to put this back the way it was? Why not just jump ahead two years and rebuild to express lanes?” Bouma was thinking much the same thing, he said. The pavement & hardware guy and the tech-whiz saw it exactly the same. They suggested it there and then, standing by the wreckage of plaza#1 to the boss, exec-director Jerry Hiebert. Back at the office Hiebert called a couple of board members who concurred. Noone could see any real problem with the jump-to-express-lanes idea apart from the fact that it would involve some hustling. Hiebert called the NTTA media spokesman JoAnn Borst, telling her “We’ve got some news. We aren’t going to rebuild. We’re going direct to express lanes.” She put the story out.

The evening news carried the crash story along with the accelerated express lanes decision by the NTTA. Borst says it was a great PR-coup, because it put a “positive spin” on what would otherwise have been a very negative story for the tollster. The NTTA was seen as capable of making a quick decision and of moving decisively to make the best of an

unfortunate accident.

The immediate plan is to fabricate a pair of equipment/sign trusses of tubular steel to span 2x2 ETX lanes down the center of the toll plaza. The toll plaza was designed for several central reversible toll lanes, and so has no central median barrier – though traffic is no longer directionally different AM and PM, and reversible lanes have not been used for several years. A continuous central jersey barrier will be installed. In addition the approaches and departures from the ETX lanes will be segregated from the adjacent manual lanes with jersey barrier stretching out perhaps 30m (100'). The exact lengths won’t be determined until a striping plan is done, Bouma told us.

Plaza#1, like most old-style plazas has small ‘belly-out’ or taper on both the approach and the departure. Bouma measured the taper length for us off plans. Plaza #1 tapers for 180m (600') compared to a 450m (1500') taper length at the new Bush Pike plazas designed for modern speeds. There have long been plans to extend the old toll plazas to provide more maneuver and waiting space for motorists. But Bouma says he doubts they will ever be implemented now, because with highway speed tolling it should be possible to reduce cash-payers to such small numbers they won’t need the side lanes or the extra maneuver space.

Meanwhile NTTA has ordered Peek’s ‘smart loops’ for vehicle classification in the ETX lanes of Plaza#1. No more high-maintenance, frequent-downtime treadles, they say. However the existing pavement in the ETX lanes does need to be broken up and fresh concrete slab poured because the smart loops are in jeopardy in any older cracked slab.

Bouma thinks the immediate rebuild and jump-to-express job should cost about a million dollars. (Money you could pay to a consultant if you were deliberative enough?)

70% ET usage

NTTA has implemented a combination of marketing and a discount to get ET usage up around 70% of toll transactions, and NTTA officials say they hope to take it to 80%. Tags can be gotten at some 70 supermarkets and credit union offices and via a huge van that visits major events and shows. On the Dallas North Tollway motorists with ET pay 60c at the mainline plazas compared to 75c cash. (Contact JoAnn Borst NTTA 214 522 6200)