The latest on Loop 1604: major traffic shifts

Since we started the $121 million expansion of Loop 1604 on the west side of San Antonio in 2016 we've somehow managed to talk about it fairly infrequently on the blog. That's because most (not all) of our work to this point has been well out of the way from travel lanes. Where only minor inconveniences exist, major blog posts do not.
All that is about to change this week with major traffic shifts for southbound traffic between Wiseman Road and US Hwy 90. These changes will also address the problem the patient folks of the Hillcrest neighborhood have been dealing with.


At Spurs Ranch
Since we've had an influx of calls and emails of late - and we certainly understand why - we'll get this issue answered first and foremost.
The posted detour for folks from the Hillcrest subdivision has been using US Hwy 90, turning around at Hunt Lane, then returning to Loop 1604. We know the detour can be really long. We ran that detour once ourselves in the middle of the day back in January. It took us about 10 minutes to make the whole trip from Spurs Ranch at Lp 1604 back to northbound Lp 1604 passing Spurs Ranch again.
Since then we've been working out solutions for the problem.
Our best bet will come after we've got traffic shifted over to the southbound and northbound frontage roads (more on that in a moment). At that point we'll have turnaround options for drivers, but there will be a brief few weeks folks will be forced to take the long detour.
Once all southbound traffic is moved onto the frontage road folks in Hillcrest will no longer be able to make that illegal move they've been making to jump across Loop 1604, against the grain, to use that turnaround just north of Red Musket Trail. Yeah, we've noticed that maneuver. Turning around through the construction barricades where the northbound and southbound lanes split won't be an option any more, either.

We are building a south-to-north turnaround at US Hwy 90 - a permanent fix for this issue - that will open up late April. This will be the way traffic from Red Musket or Spurs Ranch reaches northbound Lp 1604 forever, even after the project is finished.
Before that can be opened up we'll need to move northbound traffic over onto the new bridge over US 90 and shift traffic between US 90 and Big Mesa onto the new northbound frontage road. That's set to happen mid-April.
That shift to the new bridge will give drivers a chance to turn around at the eastbound frontage road of US 90 by way of the new signalized intersection.
By the way, we've been in touch with the heroic folks working at Bexar County Fire Department House 2, there on Spurs Ranch. We're making sure they've got a viable route to those northbound lanes to keep their response times down.


At Dove Canyon
The major traffic shift coming up will bypass - for now - Dove Canyon. Two weeks ago Webber Construction found a karst feature while digging. Environmental guidelines at both the state and federal levels require us to send biologists in to make sure the karst feature is not a habitat for endangered species.

Before we go further let's dispel any alarm. This is a very standard situation for projects like this. We're in the middle of the Balcones Fault Zone, and karst features are a fairly common thing to come across in any construction project in Bexar County or in the Hill Country. We already have displacement habitats identified should this feature be pegged as a habitat for protected species. We anticipate no threat to the project at large.
When these things happen rumors seem to fly around about how the biologists do things. What actually happens is a simple process of setting a sticky trap baited with a substance known to attract any species we know live in the area. This is usually something like peanut butter, interestingly enough. The traps are checked a couple of times a day over the period of a few weeks. Once we are given the all clear (which we fully expect to happen) we'll seal up the karst feature and you'll see southbound traffic moved onto the new frontage road to match what's happening north and south of Dove Canyon.
We expect that to happen by mid-May.


The first switch

The major change to southbound traffic will happen during the early hours of Thursday morning and will be in place before the morning commute. This will happen between Dove Canyon and US Hwy 90.
This shift holds the largest long-term impact on traffic overall, as southbound traffic will be removed from the overpass at Marbach with this change. The overpass bridge will be fitted to hold all northbound traffic while a new overpass is built to handle southbound traffic in the future. Due to the move off the overpass - and elimination of the south-to-north turnaround that goes with it - traffic engineers will adjust timing of the Marbach traffic signals. We will monitor the signals for the next several weeks to ensure the timing is optimal for all traffic directions.


The next switch

Saturday morning, beginning at 7 a.m., Zachry will move southbound traffic onto the frontage road just south of Wiseman Boulevard through Potranco Road. This shift will effectively eliminate use of the turnarounds at Military Drive and at Potranco. Traffic trying to turn around at either location will use the signalized intersection to do so. We will have traffic engineers on hand to adjust signal timing to handle the additional traffic loads as appropriate.
The shift will leave the intersection at Wiseman as-is. This means traffic using the turnaround at Wiseman to reach Northwest Vista College, the Wells Fargo Wiseman campus or the eastbound lanes of Hwy 151 will still be able to do as they are doing today. At least, for now. At some point in the future we'll need to switch traffic over to the frontage road to build the overpasses at Wiseman. That change is currently planned to take place about the middle of this summer.


Dove Canyon

The shift onto the southbound frontage road through Dove Canyon, as we mentioned above, is set to take place mid-May as long as everything pans out as planned. When that happens, don't expect major closures or anything - it'll be a simple matter of moving some barrier and will take a bit more than an hour, tops.
This will all but complete the shift of the southbound main lanes onto what will be the frontage roads when we're all done with work, allowing crews on both segments of this expansion to work in earnest on the main lanes, including the overpasses you've probably noticed start going up in a few locations.
This reduces significantly the need for lane closures as we do the work on the main lanes, particularly as we've used weekend closures to reconstruct a number of intersections already. Moving forward keep an eye out for digital message boards announcing weekend closures as we get closer to setting bridge support beams over those cross streets.


Near US 90

With traffic mostly shifted and while waiting for the outcome of the biological study at Dove Canyon Webber will have crews working diligently to finish the new northbound lanes between US 90 and Big Mesa. Getting those new lanes built, including the new northbound overpass at US 90, allows us to open up the turnarounds we discussed earlier.
The first of two turnaround options will be open the second week of April along with the northbound bridge and frontage road. By moving traffic onto the northbound lanes dirt crews can finish the turnaround at US 90 - the permanent fix for access to northbound Lp 1604 for those folks coming from Spurs Ranch and Red Musket. That turnaround will finish up late April.
With traffic shifted to the new frontage roads in both directions crews will build in earnest the main lanes and overpasses on the southbound side. Northbound work will come later this year.

The new main lanes between Hwy 151 and Potranco Road are set to open for traffic mid-2019. Work on the main lanes between Potranco and US Hwy 90, including the southbound Loop 1604 connector to eastbound Hwy 90, will finish in 2021.