Here is a similar example completed in 1971: http://en.wikipedia.org/wiki/Lowry_Tunnel
It is I-94 through downtown Minneapolis. It includes at least three buildings within 100′ of the center line, and ROW is likely tighter than that. Buildings are not any closer to the center line of the Lowry Tunnel due to the right of way required by the two surface arterial roads that intersect here (and also because some of the buildings pre-date the tunnel).
I would be interested to understand the valid limitations expressed by TxDOT. It’s not hard to believe that the Reconnect Austin envisioned graphically thus far will require some modifications due to real engineering constraints. However, since I’ve seen working examples elsewhere, it’s impossible for me to deny that Reconnect Austin’s general vision is indeed feasible, engineering-wise.
Reconnect Austin 
Here is a similar example completed in 1971:
http://en.wikipedia.org/wiki/Lowry_Tunnel
It is I-94 through downtown Minneapolis. It includes at least three buildings within 100′ of the center line, and ROW is likely tighter than that. Buildings are not any closer to the center line of the Lowry Tunnel due to the right of way required by the two surface arterial roads that intersect here (and also because some of the buildings pre-date the tunnel).
I would be interested to understand the valid limitations expressed by TxDOT. It’s not hard to believe that the Reconnect Austin envisioned graphically thus far will require some modifications due to real engineering constraints. However, since I’ve seen working examples elsewhere, it’s impossible for me to deny that Reconnect Austin’s general vision is indeed feasible, engineering-wise.
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Thanks so very much, Tom, for introducing us to this video:
We’ve been aware of the adversarial impacts of DDIs for some time, but the above pretty much sums it up! Methinks you may be interested in delving into TxDOT’s “Freeway Design Manual”: http://onlinemanuals.txdot.gov/txdotmanuals/rdw/freeways.htm#CHDECBJJ as well as “induced demand” and “disappearing traffic”: https://reconnectaustin.com/resources/traffic-studies/
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