The first rule of brainstorming is that there are no dumb ideas.
There are, however, old ideas, and Austin architect Sinclair Black’s suggestion that Interstate 35 be buried through downtown has been around in some form since at least 1996. Black himself was one of the suggesters back then as was, oddly enough, the Texas Department of Transportation.
An old idea that has never gotten traction could be considered, if not dumb, at least fraught with what could politely be called challenges.
The American-Statesman splashed the concept all over the front page in June 1996 with the headline, “I-35 underground?” Black, whose views about urban development have influenced a generation of city politicians and staff, wanted to sink the road below ground from East 15th Street to north of the Colorado River, a distance of about a mile. The only entrance and exit ramps were to be at East 15th and East Cesar Chavez streets, with boulevard-like streets at ground level to serve local traffic.
With I-35 out of sight and somewhat out of mind, downtown streets would then be able to flow seamlessly to East Austin, the thinking went, easing that sociological and economic divide. The long article did not mention a cost estimate.
TxDOT had a similar scheme, but with flyovers going from the freeway lanes to some downtown streets. Neither idea advanced beyond the discussion stage.
Black’s proposal now (which some local media have been treating as brand-new) differs from what came before basically in that he wants to throw dirt over the buried freeway. And make part of it tolled.
Black suggests that I-35 in these 14 blocks be dug deeper and expanded from three to four lanes in each direction, with the two added lanes having tolls. Running up above would be the boulevard, with north and south lanes much closer to each other than the current frontage road lanes. There would be a 10.6-acre park in the median and some development on the rest of the TxDOT-owned land alongside the boulevard.
He also envisions even more development springing up alongside the park and boulevard/freeway, which now has some large and valuable development in spots but mostly is lined by property not, in development lingo, at the highest and best use.
As in the idea’s earlier incarnation, there would be entrance and exits ramps at the north and south ends. But Black said one more set of ramps, likely around East Ninth Street, would probably be necessary as well.
Black estimates that the buried freeway and its mile-long green chapeau could be accomplished for $550 million. TxDOT could more than make up that cost, in his view, by selling 30 acres for more than $260 million and collecting $450 million in toll revenue over 25 years.
Local government, he says, would get an additional $930 million in property tax revenue over a quarter-century from all that development.
I used to be an engineer, but not a highway one, and that was a long time ago. So people with sharper pencils will have to pass final judgment on his numbers. TxDOT’s Austin district engineer Greg Malatek, given that the agency is sifting Black’s idea along with many others for improving I-35, offered no opinion on either the costs or the idea.
Just as a comparison though, TxDOT and the city of Dallas late last year completed a three-year project to put a lid on three blocks of the Woodall Rodgers Freeway just north of downtown Dallas, with Klyde Warren Park sitting atop those three blocks. The cost was $110 million for about 1,000 feet of covered freeway and park, which extrapolated to a mile would be about the $550 million estimated by Black.
However, Woodall Rodgers in that stretch was already depressed below the frontage road level. They didn’t have to bury it, in other words, just cover it.
Here, some of I-35 in the suggested tunnel/park stretch is already below ground. The overpasses at East 11th and 12th streets, for instance, are at the same level as the frontage roads, and down at East Cesar Chavez the southbound lanes are buried. Everywhere else, however, considerable digging would be required.
Black’s $550 million might be a bit light.
“Cost is not really the issue, and neither is traffic,” Black told me last week. “This is about creating value.”
Other questions: What happens with I-35 traffic during all this dirt moving? And what are the public safety implications of a mile-long tunnel?
But, as I said, no dumb ideas. Engineers, given the license, the time and enough money (whatever the real number turns out to be), can pull off about anything. Maybe even Austin’s Little Dig.