Construction on MoPac is about to begin.

Wait … what? Isn’t it finally about to end?

Calm down, North Austin. What I’m talking about is unlikely to affect you unless you’re headed to the Salt Lick or house hunting in Circle C.

As I recently reported, the Texas Department of Transportation has awarded a $53.5 million contract to build what it calls the "MoPac Intersections" project. The contractor will cut underpasses at Slaughter Lane and La Crosse Avenue, removing from the freeway the last two remaining traffic lights on MoPac Boulevard’s 24 miles of heaven between Round Rock and southwestern Travis County.

The work, which had been delayed about a year by litigation, should start in January and take until mid-2020.

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Notice I said "should." I qualify that kickoff projection mostly because of 1:16-CV-00876, better known as the Center for Biological Diversity et al. v. the Texas Department of Transportation et al. That federal lawsuit, filed in July 2016 by the Arizona-based environmental group and Austin’s own Save Our Springs Alliance, contends that building the underpass project will harm the endangered Barton Springs salamander, Austin blind salamander and golden-cheeked warbler.

The plaintiffs in their original filing scoffed at an environmental review of the project that TxDOT had done — before TxDOT itself approved the project in late 2015. Funny system, isn’t it? An agency that clearly wants to build a road is deputized by the federal government to review its own handiwork and then pronounce it exemplary. Seems to put a whole lot of faith in human nature.

Anyway, that’s what occurred. The Center for Biological Diversity and SOS, suing on the last day legally possible under federal law, argued that TxDOT in its environmental due diligence had failed to do a legally required consultation with the U.S. Fish and Wildlife Service. Their lawsuit originally asked that this consult occur, presumably under the assumption that the federal regulators would find deficient TxDOT’s conclusions about the endangered species. Not a crazy idea, by the way, given that "Fish," as insiders call it, had emailed TxDOT in March 2015 taking issue with TxDOT’s assertion that the project would have no effect on the listed amphibians and the bird.

The project will remove almost 700,000 yards of soil from that area near Circle C and add about 16 acres of paved surfaces, which tend to speed up the pace of rainwater runoff into the Edwards Aquifer, where those salamanders hang out.

But time passed, a national election happened, and things didn’t go as the plaintiffs had hoped. In June, Adam Zerrenner, the supervisor of Fish’s Austin office, issued an 11-page ruling that said the effects on the species would be at "an insignificant or discountable level" given how TxDOT intends to build the project. Furthermore, Zerrenner wrote, only one warbler had been spotted within a mile and a half of this part of MoPac within the past 25 years.

IN THEIR WORDS: Read the June letter from U.S. Fish and Wildlife

Save Our Springs Executive Director Bill Bunch scoffed at all this when I talked to him last week, calling it "junk science," implying that the regency of the Trump administration had more to do with the decision than conscientious study. But it is, of course, the job of advocates to advocate. In Bunch’s case, literally his job.

Bunch, by the way, was surprised to hear that construction of the underpass project is set to begin in January. I asked if, as was the case with an earlier federal lawsuit involving SOS, 11 fellow plaintiffs and Texas 45 Southwest, he might seek an injunction to block the start of construction on the underpasses. Bunch, assessing all of this on the fly, allowed as how that was a possibility.

I guess we’ll find out in the next couple of months on that. That similar attempt with Texas 45 Southwest was a swing and a miss, and the Fish opinion certainly doesn’t help the current Save Our Springs case. And all of this is well-trod ground for U.S. District Judge Lee Yeakel.

Assuming all this goes as is currently guesstimated by the road-builders, we could see an interesting situation on far South MoPac in a couple of years.

The Texas 45 Southwest tollway and its four new lanes connecting to FM 1626 figure to bring a few thousand new cars a day to the part of South MoPac between Slaughter and another piece of Texas 45 that juts to the west. Those people from Hays County, if they want to go to work in Austin or other points north, currently have to use Interstate 35 or take a suburban shortcut along Brodie Lane and Slaughter, then head north on MoPac.

NORTH ON MOPAC: What you need to know about MoPac’s new northbound toll lane

But because of the two lawsuits, the timing on the two projects has been reversed from the original intention. It appears now that the tollway will finish something like six months before the underpass project, assuming the latter isn’t further delayed in the courts. The traffic that Texas 45 Southwest will feed into MoPac could create a fairly epic stackup at La Crosse in the morning and Slaughter homeward bound in the afternoon, at least for a few months.

Or maybe more than a few months, depending on how the lawsuit goes. And, given what happened on North MoPac over the past four years, the construction.