From North Texas Tollway Authority e-newsletter:

Dirt Keeps Flying on Bush Extension

As construction on the President George Bush Turnpike (PGBT) Eastern Extension progresses, one thing is for certain – crews will be up to their ears in dirt as they begin the “messy” task of moving more than one million cubic yards of dirt to make way for the eastern expansion of the PGBT.
 
The NTTA is building Sections 28-31 of the 9.9-mile extension, which will lengthen the PGBT southeast from State Highway 78, over Lake Ray Hubbard, to Interstate Highway 30. The Texas Department of Transportation is building the lake bridge (Section 32). Construction began in October 2008, and the road is expected to open to traffic in late 2011.
 
Along its length, the extension will have a variety of profiles – from well-below grade to ground level and back to well-above grade. Section 28, from the Firewheel Town Center in Garland to west of Miles Road in Sachse, is largely below grade, beginning its westward trek beneath the bridge at Crist Road and also passing underneath Firewheel Parkway.
 
As a result, crews must dig down as much as 30 feet in spots, displacing slightly more than 1.2 million cubic yards of dirt, rock and other ground materials in the process – about 480,000 loads for the average full-size pickup truck.
 
While some of this dirt will be used to build embankments within the project, large haulers are standing by to cart most of it away to various off-site locations.
 
Now, weather permitting, crews are stripping and stockpiling the topsoil for re-spreading when the major earthwork and construction are done. This involves removing about four inches from the entire length, except areas that will not be disturbed in the construction.
 
The majority of the built-up areas, or embankments, for this project are at the bridge abutments, which is considered a short haul accomplished with track hoes, large eject trucks and paddle scrapers. That material is excavated, hauled, spread and compacted without access to a public roadway.
 
The remaining excess material requires loading onto semi-tractor trailers and hauling over public roadways in legal loads of about 40,000 pounds of material per trailer. That equates to about 12.5 cubic yards per truck, or about 62,440 truckloads.
 
In coordination with the corridor cities of Garland, Sachse and Rowlett, contractors already have placed some of the dirt on an adjacent property for its future development. The City of Garland will receive 50,000 cubic yards, or 4,000 truckloads for future use in the C.M. Hinton Jr. Regional Landfill in Rowlett. PBGT EE Section 30 will require about 120,000 cubic yards, or 9,600 truckloads.
 
The remaining material will be sold and hauled to places yet to be determined.
 

 
One correction to the information above: the Hinton Landfill is in Garland and is, in fact, a part of District 1. Someone unfamiliar with the city boundaries could easily mistake it to be in Rowlett though.
 
Another note: the title to this post is tongue-in-cheek. When originally constructed, the bridges at Crist Rd and Firewheel Pkwy were built almost at grade. Someone not paying much attention would have no way of knowing they were bridges except they did have side rails. The plan was to dig under the bridges when the turnpike was extended, as we are now seeing happen.