Managed Lanes: Good Theory; Will Suck Here
A short entry; and I won't inflict a drawing on you, so please use the power of your mind to visualize.
CAMPO has already tentatively allocated $110 million for "managed lanes" (one in each direction) on Mopac from Parmer to Town Lake and is now explaining the plan. These will, apparently, boil down to a new inside lane in each direction, with possibly flimsy barriers between them and the general-purpose lanes, similar to what you see on the northbound frontage road just north of Bee Caves Road. General-purpose lanes will have to be narrowed a bit, and some shoulder will be lost (especially the inside shoulder - which will be effectively gone).
I'm generally a moderate supporter of HOV lanes, and a stronger supporter of managed lanes. Tolling road capacity anywhere is a good move away from our current system in which urban drivers and especially non-drivers subsidize SUV-driving suburban soccer moms. Ironically, the more red-meat conservative you are around these parts, the more you apparently pine for the old Soviet method of market-clearing, at least as it applies to road capacity.
And, one of the best reasons to support HOV or managed lanes is the boost in performance and reliability it can give bus transit, which needs all the help it can get.
HOWEVER, the system considered here will do nothing to improve the performance of transit, for this reason:
To exit Mopac, the bus (or car that paid a toll) must travel through three lanes of general-purpose traffic in order to get to the exit lane.
If that traffic is backed up enough to make you want to use the toll facility, it will also be backed up enough that it will be impossible to quickly cut through to get to your exit. Much of the time savings in the managed lane will be lost at entry and exit.
This is the same problem other half-assed HOV facilities have around the country - in places like South Florida (no barrier; hard to enforce; and mostly useless during extremely high traffic periods except if you're going all the way through where the traffic is). Likewise, this facility won't help the commuter going to UT, or downtown; the only group it could really help dramatically would be people going from north suburb to south suburb.
IE, we're going to spend city drivers' gas tax money to even more excessively subsidize the suburban commuter - but just in case we might accidentally benefit the city; we're going to do it in such a way that it only helps those who don't live OR work in the center-city.
By the way, $110 million would pay for the entire commuter rail line (which won't do anything good for Austin), OR, it could be used as a down payment on a rail transit system which will work, i.e., build a leg of real non-streetcar light-rail from downtown up to the Triangle.