HOT IN TEXAS Dallas Plans 6-HOT lanes in new 14-lane LBJ Fwy

HOT IN TEXAS

Dallas Plans 6-HOT lanes in new 14-lane LBJ fwy

California invented the express or HOT (High Occupancy free/Toll others) lanes idea and implemented it first (SR-91 Anaheim, I-15 San Diego) but Texas is taking it big! The local concensus building team for the LBJ Freeway (I-635) reconstruction in north Dallas has recommended that the busieast stretch of the overcrowded 8-lane freeway east of Dallas Fort Worth airport be rebuilt with 8-free and 6-HOT lanes, which would make it the largest HOT lanes project yet built. The report on the “Locally Preferred Alternative,” the culmination of a ten year period of studies and community consultations, says the stretch of the LBJ between the I-35E interchange in the Dallas-Fort Worth airport area eastward 15km (9.4ml) to the US-75 interchange is “so intensely developed and central to so many trip patterns that it poses the problem of insatiable demand.” Modelling of trip patterns showed that this section could grow from the present 240k vehs/day to 600k vehs/day by 2015, which just to provide present (poor) levels of service would require 20-lanes (versus 8 now).

The manager of the Texas Department of Transportation (TxDOT) LBJ Corridor study office Matthew MacGregor told us there is now widespread agreement in Dallas that the highway must be “reconstructed and reconfigured to provide a market-driven approach to customer service,” offering choices to local citizens, raising fees from those who get superior highway service while offering a break to those who make lesser demands on a costly facility. The study says the HOT facility may be privatized. The financing needs of the HOT lanes might influence the staging of the free lanes since a balance will need to be managed to preserve the incentive to HOV and HOT. The department is sponsoring a traffic and revenue study for the HOT component, and this will be a basis for considerations about how to proceed in designing an ‘Implementation Plan.’

The recommendation of a major HOT component is supported by the TxDOT and comes from a community-based LBJ Executive Board, whose 23 members represent local cities, business, property owners, citizen and environmental groups and supported by the TxDOT, HNTB and other consultants. The panel eventually reached unanimity. It ruled out any elevated structure, in favor of at grade or below ground roadway. And it was opposed to any effort to meet unlimited travel needs with a free facility in favor of a strategy of congestion pricing on below-ground or underground HOT lanes (6-lanes) plus an ultimate 8 free congestable lanes to provide the choice of ‘free’ travel’ for a total of 14-lanes (plus frontage roads). In addition there are ‘auxiliary’ lanes for weaving and at cross-street overpasses the frontage roads are given ‘bypass’ lanes alongside the mainline lanes to avoid the at-grade intersections, so there will be a minimum 18-lanes plus shoulders making this one of the largest highways in North America. It has an approximate design capacity of 400k vehs/day, according to TxDOT engineers. HOT roadways will have their own grade-separated ramps. Still to be decided is the precise configuration of the highway. If the decision is made to acquire extra right-of way to allow for side-by-side configuration central roadways would be served by ‘wishbone’ structures (as on the NJ Turnpike or I-95 south of the Washington Beltway) which split incoming traffic and merge exiting vehicles to avoid central HOVs having to weave through the free lanes. Equally likely is a structure-heavy roadway mainly within the existing right-of-way, with HOT lanes buried in tunnel structure or depressed so free lanes can be cantilevered over them (see sections.) The LBJ corridor study has not yet decided if the HOT lanes or the free lanes should be on the outside. If the HOT lanes are outside they would go underneath the frontage roads in places, minimizing disruption of the existing mainline during construction but raising major problems of utility relocation and maintenance of access to businesses on the frontage roads during the build. More conventional would be to concentrate the structures work in the middle, putting the HOT lanes inside or underneath the mainline free lanes. If access to HOT lanes were limited to light vehicles of limited dimensions then costs of the structured highway would be considerably reduced, but the LBJ Study appears to have ruled out that economy by requiring that the HOT lanes provide for buses and even possible future rail transit.

Costs of the complete 15km highway are estimated at between $728m and $878m, the higher cost being for the HOT lanes buried under frontage roads providing continuous frontage roads. $728m would buy HOT lanes in the median adjacent to the mainline free lanes but frontage roads only where right-of-way is adequate. Like many Texas freeways the LBJ has one-way ‘frontage’ or collector roadways running alongside the mainline and connected to it by frequent slip ramps, so that there are few major interchanges. With the frontage roads (that often double as access for an adjacent commercial strip) the LBJ has a right-of-way that varies between 100m (330’) and 140m (450’). In the narrower section the frontage roads disappear.

To HOV or HOT: The Dallas area is building an extensive network of HOV lanes, most of them barrier separated, and LBJ study chief MacGregor says these could be developed into an HOT network as part of the LBJ development. The LBJ Corridor Study covers an East Section in addition to the HOT-West Section. The Eastern section is recommended to be rebuilt to10 lane of mixed traffic with 4-lanes of HOV, then 2-lanes HOV, then no-HOV, as you head east.

The LBJ highway in question (I-635) is the first motorway standard east-west highway north of the Dallas central business district (it’s about 17km north of it.) 8-lanes in width it is currently getting a pair of concurrent flow HOV lanes on the inside median. The western section is heavily congested for many hours each day carrying 14k to16k veh/hr almost continuously from 5am to 6pm. Middle of the day flows are approaching rush hour levels for a near flat-top graph in place of the familiar double peak. With the center of gravity of development in Dallas somewhat north of the CDB this has been an area of rapid growth in traffic. The Dallas North Toll Road operated by the Texas Turnpike Authority crosses the proposed 8-free/6-HOT stretch midway. The Authority currently has under construction the President George Bush Turnpike (TX-190T) as another east-west highway roughly 12km (7ml) beyond the LBJ, but also feeding into the Dallas Fort Worth Airport area. The LBJ Corridor study concluded that the Bush pike would offer only minor and temporary relief to the LBJ.

Completion of the decision on a Locally Preferred Alternative represents the end of the Major Investment Study process. A firming up of the layout and an implementation plan is scheduled for completion by the spring of 1999, followed by a start on detailed design with construction hoped to begin in 2002 and to continue in stages through 2015. (Contact M. MacGregor LBJ Study TXDOT 972 437 0101)

Terminology mess: Express lanes already have two different meanings: (1) lanes intended for through-traffic which are usually central roadways with fewer ramps or less direct connections to local streets but which are open to all vehicles (the preferred term in Texas and also used to describe the inner roadways of H-401 in Toronto, and I-270 in Montgomery Co Maryland) (2) lanes which are operated with the object of assuring free flow conditions by limiting the number or type of vehicles which can use them (these being ‘express lanes’ in California as on SR-91 and I-15 San Diego). Then we have the term HOT lanes (High Occupancy vehicles free/others Tolled) which are the same in Texas as Express lanes in California. Vee Amerikans need ein Wordfuehrer to diktate vitch vord is vitch. OberwordmeisteraufFHWA Jane Garvey pleaze dictate! Pending the chief’s terminological ruling we’ll throw our weight with the Texans and their more precise term HOT. The Californians ‘express’ lanes moniker just confuses things. We should now call 91-Express in Orange county 91-HOT!