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Thursday, February 13

Future projects: Loop 1604 (east San Antonio), Walnut Avenue (NewBraunfels)

Today Bexar County and its construction partners broke ground on a project expanding Loop 1604 to a four-lane divided highway between Randolph Air Force Base and I-10 on the east side of San Antonio. Meanwhile, in New Braunfels, utility companies are preparing to mobilize crews that will address conflicts with an upcoming expansion project on Walnut Avenue between Landa Street and Kerlick Lane.

Loop 1604

Bexar County provided the funds to make this important project happen, and they are managing the year-and-a-half of work. When the work is finished, TxDOT will buy the project from the county (so to speak) at a price that will be determined by a complex formula involving traffic counts and actual costs. Ordinarily, the purchase price for the state is around 80 percent the total cost of construction, which is $23.5 million.

This is a funding method called "pass-through financing", and it allows local contributions maximum leverage to get state funds dedicated to mobility projects. Comal County has successfully used the method a number of times, including on Highway 46 on the west side of New Braunfels.

Credit for the work to secure this funding goes to the Bexar County Commissioner's Court and the San Antonio-Bexar County Metropolitan Planning Organization. They are the entities with control over transportation purse strings, and the elected officials on those councils worked hard to ensure this work happens.

Alright ... so on to the scope of the actual project....

The work will turn Loop 1604 into a four-lane divided highway between I-10 and Lower Seguin Road on the city's far east side. Basically, it'll match what we (TxDOT) built back in 2011 between FM 78 and Lower Seguin Road. Right now the road is a two-lane country road, carrying over 25,000 cars per day. We think the expansion of this roadway will serve each of our department goals of maintaining safety, addressing congestion and connecting Texas communities. How will it do that?
  • Maintain a safe system Any time you seperate oncoming traffic from one another you are almost automatically improving safety. The risk of catastrophic head-on collisions is reduced to a minimum and a little extra wiggle room is given to protect us from others who can't seem to stay in their own lane.
  • Address congestion Again ... we're adding capacity all the way on this. The new road has an added lane in each direction to carry traffic. Gone will be the days of getting stuck behind a piece of farm equipment going 30 miles per hour when you're running late; you should be able to cruise at the posted speed limit all the way through.
  • Connect Texas communities Clearly this is an area that's growing, and the corridor is becoming increasingly important as bedroom communities in the county's eastern rural areas become more suburban. Though our 2012 numbers show the corridor supporting more than 25,000 cars per day, the same area only carried about 18,500 cars per day three years earlier. For those keeping score at home, that's an increase of more than 35 percent in just three years. Put another way, that's a bump of better than 10 percent each year. With a trend like that continuing, we could see use jump to more than 30,000 cars per day by 2015. We'd reach 50,000 cars per day by 2020. Not to mention it simply makes sense to have four lanes reaching from I-10 all the way around to U.S. Hwy 90 on the north side of San Antonio.
Anyway, as work on that project progresses the county will get updates out. Only periodically will we discuss it here on this blog.

Walnut Avenue

We've been working for a few years now on the plan to widen Walnut Avenue "up the hill" in New Braunfels. Essentially, this effort will match the winding road to the rest of Walnut Avenue/Highway 46 on either side of it, including the center left-turn lane and the bike lanes and sidewalks. The total price tag is an estimated $12.6 million for work that will take a full year-and-a-half to complete.
 
Now, that's when we get started on the work. We received bids earlier this month and anticipate announcing a contractor late February or the first few days of March. Ordinarily, that would mean seeing construction activities as early as May or June.
 
This contract has a built-in delay that will push our start to this fall while utility crews (contracted by our friends at New Braunfels Utilities) work on getting all appropriate lines out of the way before work starts.
 
Now, the interesting portion of this project is between Grandview Avenue and Howard Street. Those who drive the area routinely know there's a large rock face on both sides of the road. In order to widen the road we have to add to or take away from a cliff face. We decided to add. We also decided to make things a little easier on ourselves by eliminating the left-turn lane on this stretch. Not much call for it anyway - there's nowhere to turn!
 
In order to accomplish this widening, we'll build what's called a "Mechanically Stabilized Earth" wall on the downhill side (south side, or along the eastbound side). This MSE wall is a really big retaining wall that will range between 20 and 35 feet tall from the bottom of the wall to the top of the
 
Initially I told you we were widening the road in both directions. I was partially correct; We’re expanding in both directions along the whole area, except for the cliff portion of the project. In that area we’re going to use a retaining wall to build up the needed expansion area on the downhill side, preserving the existing cliff face on the north side of the roadway. This will allow us to preserve the rock face on the uphill slope and do all our widening on the downhill slope.
 
The length of the MSE wall? about 2,200 feet; that's nearly half a mile!
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