BOCA CHICA BEACH — Mounds of dark gravel dot the last 15.1-mile stretch of State Highway 4 that leads to the Gulf of Mexico, awaiting construction crews for a needed facelift.

The road repairs will run from the U.S. Border Patrol checkpoint to the eastern end of the roadway, which abuts Boca Chica Beach in Cameron County.

The repairs, while long in the works, are significant because this is the main — in fact, the only — thoroughfare to the much anticipated SpaceX launch site.

And a site visit last week by the Valley Morning Star revealed that to the west, just before the highway ends at the Gulf and on land that SpaceX owns, yellow-plastic “Caution” tape traces a rectangular tract of land.

It is here, on these key parcels of sand, that SpaceX intends to house several of its South Texas facilities — including the launch pad, water tower and security guard buildings.

Signage is a key indicator that the infrastructure in the area is about to get some serious attention.

Two signs announce that Clark Construction, of San Antonio, is the contractor on the road work that is planned. And temporary signs, already in place but turned away from traffic, soon will warn motorists of loose gravel.

Two power company trucks were in the area, as well, where the space exploration firm intends to develop the world’s first commercial vertical launch complex designed specifically for orbital missions.

The recent activity both at and around the project site comes as SpaceX continues to purchase land under the name Dogleg Park LLC.

Two more lots were purchased recently, bringing the land SpaceX now owns in Cameron County to more than 100 acres.

The company is in the process of replatting some of the property.

Public notices in plastic bags to protect them from the elements were hanging from a wooden stake on SpaceX land, and a few miles up Highway 4, on a vacant building, advising of the replatting plans.

TEXAS HIGHWAY 4

Clark Construction, under contract with the Texas Department of Transportation, will be making the improvements to the state highway.

“The piles of gravel that you saw are part of the seal coat program that has been in place as part of the road maintenance program for the TxDOT Pharr District,” TxDOT spokesman Octavio Saenz said on Friday.

The roadway has been planned for some time, Saenz said, and has nothing to do with SpaceX’s decision on Aug. 4 to locate at Boca Chica.

Still, the timing of the road repairs, while purely coincidental, is fortuitous for SpaceX, which will have to rely on Highway 4 to move trucks laden with materials, possibly water, and large, rocket parts and other vehicles.

The resurfacing is part of the fiscal year 2014 road maintenance program for Cameron and Hidalgo counties.

“For the fiscal year 2014, the road maintenance project let $3.8 million in Cameron County with a letting date of September 2013, $1.7 million in Hidalgo County with a letting date of October 2013, and $1.5 million also in Hidalgo County with a letting date of November 2013.

“There is an additional $2.7 million at a district-wide level with a letting date of December 2013,” Saenz said.

Clark Construction and Wagner Construction were selected for the work.

In a public advisory issued earlier this month regarding the planned improvements at several locations, Saenz noted that seal coats, also known as chip seals, are simple, relatively inexpensive pavement surfaces that are highly effective.

A seal coat is a layer of asphalt binder covered with a layer of aggregate (rock) applied to an existing paved surface, he said.

TxDOT spends close to $180 million maintaining 186,600 lane miles of roadway, and seal coats are critical in a preventive maintenance program.

Whether or not the roadway will stand up to the anticipated traffic remains to be seen, and TxDOT is not speculating.

“In regards to commercial traffic, before doing any type of project, we need justifiable data that allows TxDOT to demonstrate that a specific construction must be done.

“Whether it be done through a traffic count or safety analysis, every project needs to be data-driven for it to be justifiable to the Transportation Commission,” Saenz said.

TRAFFIC

The Federal Aviation Administration estimated, in its final environmental impact statement on the SpaceX proposal, that an average of 18 trucks would travel to and from the project site per work day during the 24-month period of construction.

However, during concrete pours for large facilities like hangars and the launch pad, up to 60 trucks would be transporting concrete to the site.

The EIS also noted that traffic during the construction period would increase by some 107 vehicles per day within the Lower Rio Grande Valley National Wildlife Refuge corridor, and within the corridor providing access to Boca Chica Beach and the vertical launch area.

This would approximately double the 95 vehicles per day currently traveling Highway 4 in the vicinity of Boca Chica Village and the beach.

Also, the maximum number of vehicle trips per day from full-time, on-site employees is projected to be 130 in 2016, increasing to 250 by 2025.

There would also be an average of two to three delivery trucks traveling each way on work days.

Direct access to the control center area would be located along Esperson Street and Eichorn Boulevard, which are small connector roads in Boca Chica Village within a few hundred feet of Highway 4, according to the EIS.

Eperez-trevino@valleystar.com