Headed north on U.S. 59 near Reading Road, Grady Mapes easily sums up why workers are widening miles of the freeway through Fort Bend County as part of one of the largest ongoing highway projects in the Houston area.

"You can see the development out here," said Mapes, area engineer for the Texas Department of Transportation in Fort Bend and Waller counties. "Right here, Brazos Town Center drives a lot of this."

The commercial area at FM 762 is just a portion of the development expected to greatly boost the need for the much wider highway in both directions. Drive southwest, and signs advertise new homes planned for the four consecutive freeway exits.

As it has in many communities ringing Houston, housing and commercial growth has strained once-rural highways - even major ones such as U.S. 59. The work will make U.S. 59 at least three lanes in each direction to Wharton County and bring HOV lanes deeper into the suburbs. Nearly $420 million in work is ongoing along more than 22 miles of the freeway, making it roughly 80 percent of all the TxDOT spending in Fort Bend and Waller counties.

"The need is today," Fort Bend County Precinct 4 Commissioner James Patterson said this week. "The whole project, all the way to the county line, goes into the future (traffic demand)."

Construction, however, takes time, officials said, and despite seeing a lot of new pavement along U.S. 59, it will be months before drivers have an orange-cone-free freeway. Some lanes could open later next year, though it is far too early in construction to have firm opening dates. Tentatively, new lanes could open in October 2017 at the earliest, though Mapes said utility and right-of-way issues have slowed progress.

"If I can open the northern end, safely, I am going to do that," Mapes said. "We just don't know right now what that's going to look like."

In the interim, the freeway remains two lanes in both directions - albeit lanes are narrowed making travel with trucks tricky, slowing some traffic - though major detours are planned.

Brad Daugherty, 43, said so far his commute from south of Rosenberg to Katy for his job as an apartment complex manager hasn't changed much.

"It's slower, but it's always been slow," Daugherty said, noting the freeway improvements helped sell him on the area as growing and a good investment.

Patterson said not only are residential and commercial developments putting more cars and pickups on U.S. 59, but truck traffic is also increased. That's one of the reasons state and local officials made a priority of developing Interstate 69, which through the Houston area is replacing U.S. 59 by improving the highway to interstate standards. The current work is part of that process.

"I-69 is going to be carrying more and more truck traffic not only from Mexico but from the container terminals," Patterson said, noting a rail container terminal southwest of Rosenberg is also seeing increased activity that's putting more trucks on the road bound for Houston and beyond.

The highway project is broken into four segments. From Crabb River Road to FM 762, crews are expanding the freeway to four general use lanes in each direction, as well as extending the HOV lane in each direction along U.S. 59 to FM 762.

Southwest of FM 762, crews are widening the freeway to three lanes in each direction and adding frontage roads.

Williams Brothers Construction was awarded all four of the segments. Often, contractors who secure a major project can bid lower on nearby projects because they already have materials and crews in place. Williams Brothers also has nine of the 13 contracts related to the 38-mile widening of U.S. 290.

Work occurs in fits and starts on U.S. 59. As drivers sit in slowed traffic as workers fix a pothole in the northbound lanes, about a half-mile of the future southbound lanes sits ready for lane markings, seemingly days away from carrying vehicles. But it will likely be months before any vehicles beside construction trucks traverse the lanes.

Crews first have to prepare bridges for the new lane configuration, including swapping how Reading Road, Williams Way and FM 762 connect with the freeway. Reading and Williams now go over U.S. 59 via bridges.

"We're completely flipping the roads," Mapes said. "These are more of a rural design now. This changes to a more urban or suburban design."

Swapping bridges for freeway overpasses, though, will change traffic patterns frequently for drivers. Similar to some of the work on U.S. 290, Fort Bend commuters will continue to see U.S. 59 move around the construction area. Crews working in the middle now will finish their parts of the job, and traffic will move to some of the new pavement as construction moves to the outside of the freeway.

In some spots, the main lanes of the freeway might be diverted to the new frontage roads so the finishing touches can be put on bridges and future freeway lanes.

Workers and transportation officials are juggling a host of considerations. U.S. 59 along much of its Fort Bend County route is the community's de facto Main Street. In Kendleton in southwestern Fort Bend County, the highway really is Main Street.

Though there are gaps, the freeway is lined with commercial properties, making it crucial commuters and shoppers can still access roads. Brazos Town Center, located between Reading Road and FM 762, is responsible for 30 percent of all the sales taxes paid in Rosenberg, said Randall Malik, the city's director of economic development.

"Some of the road closures, unfortunately, will have an effect," Malik said, noting so far sales tax collections have not decreased because of construction.

To avoid issues, Malik said the city and TxDOT hold meetings to both raise awareness of upcoming closings and offer ideas to lessen the effects of road detours.

"While it is a little painful during the construction, overall it is going to be a tremendous project," Malik said.