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Managed lanes on Mopac: gridlock

Just sent to Council as a followup to yesterday's crackplog

Your Name: Mike Dahmus Your e-mail address: mdahmus@io.com Subject: Managed lanes implementation on Mopac Comments: Dear Mayor and Council Members:

While I support managed lanes in general, the implementation being discussed for Mopac will be a disaster, and is not worthy of our support. Any facility in which express traffic must then cut across general-purpose traffic in order to exit will surely devolve into gridlock - if traffic in the three general-purpose lanes is bad enough to make people want to pay to drive in the inside lane, it will also be bad enough to make it difficult to quickly cut through those same three lanes to get off the highway. Which means that vehicle slows down, and eventually stops, as it tries to get over; which means through traffic in the 'managed lane' must also slow or stop.

This is a really dumb idea. Managed lanes without separate exits are worse than nothing at all. Please don't continue to let TXDOT get away with this foolish and naive design, paid for with the gas tax money collected from our urban drivers.

(An aside: for the money spent on this facility, we could make a down payment on a real urban rail system - i.e. true light rail running in reserved-guideway, say from downtown up to the Triangle or so).

This entry was posted in the following categories: Austin , Driving in Austin , PS: I am not a crackpot , Transportation


Looks like we'll get to see the plans at the April open houses. Apparently, fixing the downtown MOPAC interchanges would take $150+ million -- not something that will happen anytime soon.

Meanwhile, the question I keep asking at the open houses is "what's your criteria for success?" I'm still waiting for an answer.

Just downtown won't cut it anyways; the original plans had HOV exits at roughly 2222 and 35th street - the latter for UT service and medical centers on 38th; I don't know what 2222 would have served.

I just can't believe that once again I'm the only person asking this kind of question: what happens when I try to get back over three lanes to the right to exit the highway, but those three lanes are backed up with the traffic I paid $5.00 to escape? Doesn't the fact that I'll have to slam on the brakes to cut in mean all the people behind me in the managed lane will have to stop too?

Do you have any idea what percentage of rush-hour traffic along the Parmer-to-downtown-strip of MOPAC is due to drivers going all the way along that strip before they exit? If most of those drivers are going the entire distance before exiting, could you just make it an express lane and avoid much of the problem you identify?


Good question. My gut feeling is that there's a small but non-trivial number of people going all the way from south Austin to perhaps US 183, based on high-tech employees' residency and office patterns. Probably not enough to justify a true express lane, though (that would be far more useful over on I-35).

I have no idea what volume would justify an express lane. But if the problem you point out is a significant one, it seems like it would be worth the effort for CAMPO to try to determine that volume and whether or not an express lane would provide a better resolution that a managed lane.

I would assume (??) that no type of lane is a complete solution, so I would look then to identify what type of lane would provide the most relief for congestion. Although frankly I don't understand why they are focusing on managing traffic rather than reducing it (ie, working toward a rail solution that alot of people will actually use).

I found a plethora of information at A&M's Texas Transportation Institute website (http://tti.tamu.edu/). They even have a dedicated area to managed lanes: http://managed-lanes.tamu.edu/

The most relevant report with details in it seems to be this one: http://tti.tamu.edu/documents/0-4160-25.pdf

Now, the only managed lanes I am familiar with in Texas are those up in Dallas, and I only know a little bit about them. TTI's studies seem to indicate relative success from the HOV lanes in Dallas (http://tti.tamu.edu/publications/researcher/newsletter.htm?vol=38&issue=2&article=11), but I'm not sure that kind of success can be duplicated on MoPac in the way CAMPO seems to have in mind. My impression of travelling MoPac during gridlock has been that the destination areas in the morning and origin areas in the afternoon are much more concentrated than in a Dallas situation, where traffic seems to be more evenly spread out.

The TTI study seems fairly comprehensive on the effect of weaving across regular lanes from a managed lane to reach an exit and offers this interesting caveat that probably applies most relevantly to Austin:

"Under moderate volume freeway conditions (i.e., LOS C or D), researchers recommend a
maximum weaving volume of 450 vehicles per hour between any given freeway entrance and the
next downstream managed lanes entrance (and conversely, for any given managed lanes exit and
the next downstream freeway exit). Under high volume freeway conditions, a maximum
weaving volume of 350 vehicles per hour is recommended for the same conditions. In corridors
where freeway ramp location, spacing, and origin-destination patterns cause managed lane-related
weaving volumes that exceed these values, it is recommended that direct access from
park-and-ride/transit facilities to the managed lanes be provided."

And here's the other thing.

While it might be possible to salvage the managed lanes approach on MoPac with custom direct access ramps, it seems to me that such a project would enhance the cost by quite a bit. And then where will we have gotten, really?

We would have made it a quicker commute for suburbs to central city? While I have a great many friends and coworkers who live out north of town (and northwest), I'm not sure I'm down with making their lives easier while the rest of us who made the sacrifice to live in town are getting the shaft.

I'm pissed that I live less than eight miles away from work (Crestview to downtown), and the best non-car option for me is 45 to 50 minutes of stomach-churning bus travel time, door to door.

Mike, I completely agree with your letter. It seems that time and time again the transportation powers that be here, from CAMPO to Cap Metro, lack the political will and guts to ever do more than provide "pretend" transit solutions.

We need to stop acting like we support improvements in our transit system and start doing the things that might actually make transit work.

Mike & Pel:

The flyways to connect MOPAC HOV lanes and 35th street died since they would have blocked the view from the fine folks (with clout) at Westminster Manor whose western view would have changed from sunset and hills to cars and the flyover.

I agree that we're not going to solve MOPAC's long-term congestion problem until we figure out how to get folks on express busses and trains. This means giving up existing land and/or lanes for the express routes.

Each time I punch in a trip into CapMetro's planner, it makes more sense for me to drive & find parking than for me to take the bus. Until public transportation is faster than going by car, folks aren't going to take it. Where I lived up north, there were dedicated lanes and expressways for buses. Until folks are willing to give up express lanes along MOPAC, Lamar, Burnet, Guadalupe, etc. I don't see the congestion getting fixed.

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