DALLAS TX:Broad turnpike vs skinny tollway

They are both 2x3-lane toll roads but the contrast in scale couldn’t be greater. The old one, the Dallas North Tollway was built in the right of way of an abandoned railroad – the Cotton Belt Railway’s line from St Louis MO. It is crammed into about 30m (100'), mostly depressed, between vertical retaining walls. Shrubs and trees of neighboring yards grow out over the righthand roadway shoulder, it’s so tight. Extra slivers of residential property had to be acquired for the interchange ramps.

The new President George Bush Turnpike is spread out over more than four times that right of way. It is mostly set in a 137m (450') wide corridor. I had read and written those numbers previously, but its gargantuan scale only really sinks home when you actually see, and drive it. It’s similar in scale to the dual-dual sections of the New Jersey Turnpike and they have 12 and 14 travel lanes in a 3/3/3/3 and 3/4/4/3 configuration.

Actually neither the North Texas Tollway Authority which built the Bush Turnpike, nor its predecessor Texas Turnpike Authority (disbanded 9/1/97) dictated the scale. The state’s Highway Department initiated the roadway reservation for what it designated Future (State Highway) SH-190. And when there wasn’t tax funding it was turned over to the tollsters to build in the mid-1990s.

There’s a useful “History of the Texas Turnpike Authority” by Jesse Sublett, a 96 page book, undated and without any official publisher listed but apparently put out in 1993 on the 40th anniversary of the TTA, apparently by the TTA. It mentions a handful of projects being investigated for construction but not the Bush Turnpike. The first part of the Bush pike opened for traffic in Nov 98. Today it is taking 165k tolls/day (about 70k trips) on 24km (15mi) of road now open from Midway just west of its interchange with the Dallas North Tollway over the North Central Expressway (US-75) to TX-78 to the northwest of the CBD. Another short portion has been opened westward of Midway of the third segment now under construction of a 10km (6.3mi) leg west to I-35E. The whole of this is due to open late this summer.

The next leg in the west known as Segment IV that turns south from I-35E is delayed. Only 8km (5mi) in length it goes along the floodplain of the Elm Fork of the Trinity River to a proposed interchange with I-635 (LBJ Freeway). This segment has doubled in cost because its alignment has had to be shifted, the length elongated, interchanges complicated, extra land is needed, and elevated structure substituted for embankment. In addition the Tollway decided to build to 2x3-lanes instead of 2x2 lanes and the bridging is all being built now for the eventual 2x4 lanes, so it’s buying more road than it initially planned. Overall the Bush Pike is costing $1.2b or about $4.2m/lane-km ($6.7m/lane-mi). The troublesome segment I-35E/I-635 looks like costing a third of the total cost or $8.8m/lane-km ($14.2m/lane-mi).

Forest of concrete trees rising

Meanwhile a forest of concrete ‘trees’ is growing down at the southern end of this leg, supporting piers for the roadways and ramps of the Bush Tpk/I-635 interchange and a turnpike segment of what is designated TX-161 that angles southwestward down the eastern boundary of Dallas-FW airport. This segment V, another 6.5km (4mi), should open in mid-2002. So the segment IV will represent a missing gap for about two years.

This is a link to an existing TX-161 freeway that via TX-183 goes to the front door of the big airport.

But the Bush Turnpike keeps growing, There are studies for building another segment of TX-161 as turnpike from TX-183 due south to I-30, another 8km (5mi) through Grand Prairie. I-30 is the old Dallas-Fort Worth Turnpike (1957-1977) the first tollroad built by the Texas Turnpike Authority and the first in the state in the motor-vehicle era. At the eastern end in Rowlett a 14km (8.5mi) extension is being studied TX-78 down to I-30/East. Five different possible alignments are being discussed with local residents. All involve a bridge over western arm of Lake Ray Hubbard. Planning director Chris Anderson says 2007 is a tentative opening date. Those two extra segments would complete 68km (43mi) half loop around the Dallas area I-30/W to I-30/E.

The Bush pike’s first segments have large mainline toll plazas. The first opened (numbered 6 and 7) are vast mainline plazas with 18 and 20 toll lanes each. Three more 18-lane mainline plazas are under construction or in design. On four segments there are a total of 26 ramp plazas 23 of 2 toll lanes and 3 of 3 lanes, for a total of 129 toll lanes.

The mainline plazas on the Bush turnpike have scored a couple of firsts. It is the first tollroad in the world to rely entirely on ‘smart loops’ and signal processing algorithms for vehicle detection and system triggering, vehicle classification by axle counting and vehicle separation. Rick Herrington, IT director at NTTA says they tried a more conventional arrangement of Traffix-2000 treadles (a British product) and light curtains in the first ETX lanes. Despite major efforts they were unable to get this system working properly at speed. Moreover like all treadles they promised high maintenance costs, and regular downtime with the need for lane closures.

Love ‘em smart loops

Herrington is completely sold on ‘smart loops,’ a system called Idris from Peek Traffic Systems [UK company, US rep in Tallahassee FL 850 562 2253.] He says so far they have worked extremely well and the one system does triple duty of detection, classification and vehicle separation. He’s delighted at the thought of banishing light curtains because of the constant cleaning they need. [The Delaware Turnpike was the first to use smart loops, and since then Illinois Tollway and Orlando at its Western Expressway have implemented it, but the Bush Turnpike is the first full system reliance on this technology. Herrington says smart loops will also be used at the soon-to-be-installed ETX lanes at the NTTA’s busiest plazas #1 and #2 on the Dallas North Tollway.]

On the Bush Turnpike the NTTA are also the first in the US to provide for 2x4-toll lanes of electronic toll express (ETX) with 2x3-lanes now operational at the mainline plazas, but the fourth lane each side ready to be opened for operation when traffic warrants.

[So far ETX lanes have been constructed on 3 plazas on E-470 in the Denver CO area, 2 plazas on the Oklahoma Turnpike, a single plaza on Atlanta’s GA-400, CA/91-Express lanes, I-15 HOT lanes San Diego, 8 plazas on Houston’s toll roads, 5 toll plazas on the TCA’s 3 toll roads in southern California, 5 toll plazas on the Illinois Tollway, and at a single toll plaza IC-6A on each of the NJ Turnpike, the Biddles Corner plaza of the DE-1 Delaware Turnpike and the Western Expressway in Orlando FL. Subject to correction none of these are more than 2-ETX lanes/direction, so NTTA can claim the first 3-lane ETX arrangement in the US. Canada’s 407-ETR was probably the world’s first with 3-lane ETX tolling, and Melbourne’s City Link beat out Dallas with several 3-lane ETX and the world’s first 4-lane ETX on the northern Tullamarine toll point.]

Signage

The Bush Turnpike has a brilliantly readable manned toll booth sign – a black silhouette of an attendant in a booth on a yellow background (see above.) It is far more quickly and easily understood than conventional ‘CHANGE GIVEN’ signs. ET is signed on the NTTA tollroads with a large ‘T’ (for toll tag) on a garish but very striking pinkish-orange circular background.

The Bush Turnpike mainline toll plazas are set up with the ETX lane approach and departure zones separated from the manual lanes with a 1.8m (6') wide striped and jiggle-bar equipped buffer area. In most applications of ETX this separation is made by concrete Jersey barrier. At present traffic density with plenty of maneuver space in an uncrowded plaza the lack of a full barrier doesn’t seem likely to create problems. However officials say there are already drivers cutting across the striped buffer zone and entering the ETX lanes at a substantial angle. They may have to install concrete barrier to prevent this happening. At the very heavily trafficked Dallas North Tollway, they are taking no chances with ETX lane approach/departure separation. They will get concrete barrier right off.

Tolls for cars are 75c cash, 60c ET on the Dallas North mainline plazas and there are ramp tolls of 40c, 45c and 60c. On the Bush pike cash and ET car tolls are the same: $1 at each mainline plaza and 25c and 50c at ramp plazas. The Bush turnpike uses Ascom coin machines which NTTA officials say are superior to the CS Route machines they use on the Dallas North Tollway. They plan to replace these with Ascom machines. (Contact Jo Anne Borst 214 461 2065 www.ntta.org)

CRITICISMS: The four 18-lane and the 20-lane Bush Turnpike toll plazas seem grossly over-sized for the traffic. By the time they are opened 80% of vehicles on the roads seem likely to be using the ‘Toll Tag’ electronic toll (ET) transponders and 2 or 3 manned lanes each side would seem adequate for non-transponder equipped vehicles. In fairness, these vast mainline toll plazas were designed back in 1996 and 1997 when ET usage was about 35% compared to 67% now and the prospect of 75 to 80% within about a year or so.

And this is an esthetic judgment: we find the toll plaza structures of the Bush Turnpike heavyhanded and unattractive with their heavy box beam and box post theme. And they look unbalanced and illogical with the backs higher than the fronts. At least motorists won’t miss the toll plazas. You could probably see them from space like the Great Wall of China.

SEMANTICS: We like the use of the old English term Turnpike which seems to have been falling out of favor a bit recently. Though there is no logical distinction, the term turnpike is generally associated more with rural type tollroads that go between cities rather than tollroads within cities which tend to be called toll roads, tollways, expressways, or parkways. Of course the Denver-Boulder Turnpike and the Dallas-Fort Worth Turnpike were in their day rural tollroads, albeit shorter than the great turnpikes of the northeast, but by now they traverse heavily built-up areas.

An NTTA official told us the reason why the President George Bush was called a turnpike rather than a tollway, like the Dallas North, was quite simple. Jim Griffin the then executive-director said he liked the term ‘turnpike.’ So turnpike it was. They abbreviate them DNT and PGB or the Tollway and the Turnpike.