Digging into the newest congestion numbersSo the Texas Transportation Institute at TAMU came out with their 2007 Urban Mobility Report last week. In case you missed the story in the Chronicle, it's steadily getting worse in Houston, now up to 56 hours of average delay per traveler per year, which is 7th worst in the nation. On the plus side, we're only 2 hours/year over the average for very large cities (54), and only 12 hours/year over the national average of 44 hours for the 85 cities studied. That's less than 3 minutes of penalty per workday for commuting in Houston vs. the average major US city.
Some other interesting points I found in the report:
- Multi-billion dollar transit systems don't seem to help alleviate congestion too much: DC and SF are worse than Houston, and NYC, Chicago, and Boston are each only slightly better, with 46 hours of annual delay. NYC and Chicago actually have a worse travel-time index than Houston (ratio of trip times at rush hour vs. off-peak), with 1.39 and 1.47 vs. our 1.36.
- In the main report, Exhibit B-36 pg. 130 (B-52) has a graph showing not just Houston's change in travel times through the day, but how much margin time you have to put in your travel planning to be on-time for 19 out of 20 trips. It's very substantial, and a lot of that time goes to waste, as people arrive early at appointments. This is a strong argument for congestion-priced toll lanes, which give people the option of a guaranteed fast trip when they need it. People who need to be somewhere at a specific time can pay for it, and save the time they would otherwise waste leaving extra early "just in case." People on a more flexible schedule can stay in the free lanes.
- "Can more road space reduce congestion growth?" Their answer is essentially 'yes':
"The analysis shows that changes in roadway supply have an effect on the change in delay. Additional roadways reduce the rate of increase in the amount of time it takes travelers to make congested period trips. In general, as the lane-mile “deficit” gets smaller, meaning that urban areas come closer to matching capacity growth and travel growth, the travel time increase is smaller."
That same appendix also has a graph on pg.3 clearly showing that cities that made a better effort to keep capacity in line with growth (such as Houston) experienced far slower growth in congestion than those cities that let it get away from them. In fact, when ranked by how much worse our congestion is vs. 1982 (when the study started), we fall dramatically to 27th, which reflects our strong capacity increases over that period.
- Our I-10 project gets featured on pg. 23:
"Constructing transportation projects quickly and with as little extra delay as possible requires a mix of strategies, just as the regional approach to congestion relief. The Katy Freeway (I-10 West in Houston) expansion project includes additional mainlanes and high-occupancy toll lanes, in addition to reconstructed pavement, noise walls and landscaping. The regional toll authority purchased the right to operate the toll lanes using funds generated over almost two decades of successful toll operation in other corridors. The accelerated cash flow enabled the Texas DOT to decrease the construction time from 12 years to six years. The increased cost of the 24-hour construction schedule was partially offset by savings in construction cost inflation that would have occurred. The estimated $2.8 billion in benefits that resulted from six years of improvements in delay, lower fuel consumption and improved business environment more than offset the estimated $300 million in extra costs."I'd love to see that kind of math applied to more projects in Houston.
One of the points I keep hearing over and over laments that "if we build more road capacity, it'll just fill up," implying we shouldn't bother. I believe the Chronicle editorial board even made this point, although I can't find it online to confirm. This argument really bugs me. Do you ever hear people say, "Ugh, why build more airport runways - the airlines will just fill 'em up with flights," or, "You know, if we expand the port, it'll just fill up with more ships and trade."? No, you never hear that, because people realize those are good things to have happen. Yet, somehow, expanding road capacity to enable more economic activity and better access to jobs and affordable housing for more people is a bad thing? I don't get it.