Anybody who has read this blog for any period of time, knows that I have advocated the completely insane idea of highway removal, particularly to alleviate the choke hold the highways apply to a suffocated downtown. Some American cities have already done it or are in progress of doing it (See: Milwaukee, San Francisco, Portland, and Oklahoma City) and others are contemplating it (See: Baltimore, Seattle, New Orleans, et al).
The purpose is to ameliorate the negative effects freeways have on adjacent and nearby property, while allowing for the qualitative improvement (ie economic development) of that same property in order to build the kind of density that can support infrastructure. Under the guise of highway construction as "job creation" (which is only temporary), we have managed to build more infrastructure with very low density. You would have to have imaginary Dubai funny money to sustain that equation.
I see two choices: either admit that we can't afford the world we have built or completely wreck the globe in another world war and loan the world the capital to rebuild. Oh right, it's the American cities of today that look like they were ravaged by WW2. And you think I'm joking that we could use a "homeland Marshall Plan."
The fundamental purpose of highways is inter-city commerce/trade/and travel, not intra-city. They are not, and can not be designed to a level to NOT obstruct the fine-grained inner-workings of micro-economies, which is why cities typically try to keep highways to the periphery. They never come into contact with the city whatsoever without being tamed by an interchange and converted into a boulevard as it enters the city.
Based on highway design, the negative impact occurs to varying degrees with at-grade being the worst, above-grade "hovering" freeways being second worst, and sunken freeway (or buried) next worse. None exactly are good, and all of the efforts from the Big Dig to the Woodall Rogers Deck Park are extraordinary costs just for mitigation; to get minimal return when the biggest return on investment of all, is to either not have it in the first place or remove it.
I have argued that downtown Dallas is effectively functionally an approximated ten-block area that works precisely because of the highway loop. Main Street needs a quarter-mile buffer and a halo of high-rise towers to pretend that they aren't there.
Furthermore, it is not only possible, but probable that the highest and best use of all that land currently dedicated as 35,000+ surface parking spaces in DTD is just that parking, or the delivery mechanism for workers to jobs.
However, with that said, I also strongly advocate for incrementalism. Complex systems do not adapt well to rapid change. Which is why I suggest little victories like removing clover leaf exits in favor of more context-sensitive and spatially efficient design solutions.
Another incremental solution, somewhere between step 1 and step 50 is a solution emailed to me by friend, local architect, and globetrotter:
After you posted about taking out the elevated freeway loop around downtown I started looking at Google Earth to see if there were ways to route the Interstates to eliminate the need for the loop. This is what I came up with.
Since they are already going to tear up I-30 from the US80 split to add more lanes, I figured why not just change the path, so that it no longer slices apart East Dallas neighborhoods? So, this takes is along an existing Rail path (Union Pacific, I believe), following the Whiterock lake run-off until it eventually merges with I-45/US175 and follows the Trinity Levees until it all merges with the I-35/Woodall Rodgers interchange.
Basically eliminate the Eastern edge of the loop and the parts of I-30 that scar East Dallas the most. I-45 would be Re-Routed along the Trinity Levees as well, concurrent with I-30. The Western edge of the Mix-Master including I-35 would also get pushed to the Trinity Levees as well. In effect, the proposed route for the Trinity "parkway" becomes the new Mix-Master.
I figured this could be a decked freeway with a nice pedestrian promenade on top that has great views of the Great Trinity Park (if that ever happens). Are you familiar with the Brooklyn-Queens Expressway as it passes Brooklyn Heights? This is very similar. The traffic lanes are stacked with a Promenade above. Great views of Lower Manhattan, and you barely realize there are hundreds/Thousands of cars zooming below you. Anyway, this is 50 year plan stuff as you have mentioned, but this could piece East Dallas back together and link downtown with Deep Ellum and Deep Ellum with Fair park etc.
So with that said, I decided to look at what Toby had drawn and apply some graphics. The above shows the amount of property that would be directly affected from a re-routing or removal, repositioning it for qualitative improvement, aka intensification. Furthermore, that doesn't even begin to take into account what kind of effect it would have on Tennyson and Fair Park, by bringing them back into the proverbial tent.
Then we overlay those areas in new development.
Like any idea worth talking about, this has some pros and cons. I'm sure there will be more, but these are off the top of my head in the five minutes I have between now and running out the door.
As he points out, the timing is good. I-30 is being redone. I know the designs are already well down the road, but if you are driving off a cliff do you stop and check directions to make sure you are headed the right way?
This removes highways from the neighborhoods they have wrecked, essentially enlarging downtown even more so than what Fort Worth did with I-30. Kudos to them for doing so.
It repositions the most challenged areas near downtown, those physically isolated by freeways, railroad and floodways. Fair park is allowed to be part of the city again.
It funnels an awful lot of traffic to just one choke point where 45, 35, and 75 would essentially come together. This portion of the road would only further entrench the disconnect between downtown and the elusive dream that is the Trinity. Perhaps this choke point becomes a toll?
At this point, you might as well, just allow the outer 635/20 loop to handle the bypass traffic and downgrade the highways through the City to boulevards. You don't want bypasses because you still want that lifeblood flowing through the city. You just don't want it whizzing past at 75 mph.
I do know that I need to spend more time thinking about this. What do you think?