Surface transportation innovations for HoustonI was recently able to catch up on a stack of Surface Transportation Innovations newsletters from the Reason Foundation, and thought I'd pass along some of my favorite items:
- Why the Obama administration's plan for inter-city high-speed rail is problematic.
- Committee charts future for public-private partnership toll roads in Texas.
- Why calls for increased mass transit spending in the next federal budget are flawed: a study shows that MPOs (like H-GAC) are already planning substantial increases in transit spending - on average 40% of all transportation spending to cover only 5.5% of trips - although transit trip share is not expected to increase with the spending, and congestion will dramatically increase along with the number of suburb-to-suburb commuting trips. The solution?
“Rather than pouring billions more into rail transit lines that will serve only a small fraction of urban trips, it would make better sense to add highway infrastructure that does double-duty by providing motorists with a congestion-relief alternative and transit agencies with high-performance guideways for region-wide express bus (Bus Rapid Transit) service. A network of Express Toll Lanes added to the freeway system would do just that.”
- How do we build that HOT-lane network affordably? An innovative new answer:
"The basic concept calls for converting the left-most lane of a freeway (whether it's HOV or general purpose[GP]) to HOT, and simultaneously converting the right shoulder to a peak-period-only travel lane. Thus, no "free" lanes would be taken away, and the HOT lane would represent a net addition of peak-period capacity."
The study also shows that the benefits are substantially larger than the costs, and that tolls should be able to cover costs. This idea is absolutely perfect for Houston, and the prime first candidate would be the 610 loop, which lacks HOV lanes and absolutely needs the relief. If you know the right person, please pass this along.
- Another idea tailor-made for Houston: making new congestion-relief capacity more affordable:
"...AASHTO Highway Capacity Manual's standards for expressway design are based largely on two underlying assumptions: these roads must be safe for travel at high speeds, and they must all be able to carry mixed traffic, including large trucks. They then ask the logical question: if urban expressways are congested much of the day so that only a small fraction of their daily traffic can operate at high speed, should we still design to standards based on those high speeds? And also, should we design every major roadway to accommodate large trucks?Essentially, they're arguing that we convert more of our arterials to be like Allen Parkway, which everybody I've talked to seems to think is a fantastic idea. It could certainly take a lot of the load off the freeways. There are many great candidates for such a treatment: outer Westheimer and 1960/Hwy6 immediately come to mind. Nominate your favorites in the comments.
In the paper Ng and Small then explore the trade-offs involved in narrower lane and shoulder widths (which result in lower design speeds) to make possible an additional lane in each direction, on both expressways and major arterials, within the same total width. For approximately the same construction cost, the expressway or arterial with more lane capacity wins out in most cases where peak-period traffic volumes are much greater than off-peak volumes. The "narrow" designs are strongly favored in all cases in which there is appreciable queuing—i.e., serious congestion. That's because the slightly lower free-flow speeds of the narrow designs pale in comparison to their much greater ability to handle traffic before flow breaks down.
The other important comparison Ng and Small make is between a full-blown expressway and a super-arterial with grade separations (overpasses) instead of signalized intersections. Here they compare roadways with equal capacity but different costs to construct. They find that the unsignalized arterial is more cost-effective than an expressway of equal capacity under most scenarios, "because the difference in travel-time cost is relatively small while the difference in construction cost is much higher."
...a good network of six-lane arterials, Swenson proposed converting some of those arterials into a new kind of managed-lane facility. "Queue-jump" overpasses would be constructed at major signalized intersections, with four lanes on the overpasses and two retained at grade (plus turn lanes). Electronic tolls would be collected from those using the overpasses, but no one else. Thus, the concept would not violate the accepted Florida principle of charging tolls only for new capacity, not on existing roadways.
Swenson developed cost and traffic estimates for one such corridor that would involve building six queue jumps. Preliminary calculations suggest that the costs could be recovered via toll-revenue financing."
A final note: I'm on vacation for the rest of the month, and may or may not be able to post from the road. However it works out, posting should be back to normal the first week of June.