Only One Question Matters on Mopac Managed Lanes

My favorite band (local) from the early days here in Austin – but in a later incarnation I didn’t like as much, there medications explains:

Ben Wear did a great job covering all the other issues but somehow still neglected to discuss the performance implications (for the managed lane itself) of the fact that drivers must slow down to a crawl in order to merge back through 3 lanes of regular traffic to get to their off-ramp. (I’m a supporter of managed lanes in principle, view but like with commuter rail, and believe that Something I Like But Done Completely Wrong is actually more likely to hurt my cause than not doing it at all).
That’s the only question that matters: how much will traffic in the managed lane have to slow down when I have to stop to wedge my way in the inside general-purpose lane?
I’m beginning to think most transportation issues boil down to one question like this. For instance, look for commuter rail it’s why do you think the same people who avoid buses like the plague today, even the good ones like the 183-corridor express buses, are going to be willing to take a shuttle bus to work every day from the train station in East Austin?
For Rapid Bus, it’ll be if this is so wonderful for Central Austin, why has it been pushed back from an originally planned opening date of 2006, then to 2007, then to 2008, and now to 2010?

  • Any surface level transportation solution, including additional lanes, buses and street cars will still suffer from surface congestion. Where’s the benefit to me as a rider, if I’m still stuck in surface traffic, and now I’m on a bus or train?
    Seems like you’d want to either raise the rail (monorail) or bury it (subway) to gain the advantage of reducing surface traffic.
    And adding additional lanes, even managed, or carpool lanes is a false promise of improved throughput. There’s a diminishing return to adding additional lanes because as you point out, you still have to merge to enter and exit.

  • mdahmus

    WRT rail (and even bus), it’s important to distinguish between grade-separated (elevated or subway) and reserved-guideway (no cars in my ‘lane’). Reserved-guideway gives you 99% of the benefit of grade-separation at a small fraction of the cost – which is why light rail lines have done so well in this country compared to buses. The expense of grade separation after the fact is rarely worth the cost – but some people are using this to confuse people into thinking that you can’t build ANY rail which is worth it, which is not true at all. Just do what Dallas, Portland, Salt Lake, Denver, Minneapolis, and heck, even Houston have done – and watch it work.