I see the methodology being used in this story about a cost/benefit study of building overpasses for streets where freight trains block a lot of traffic, but I'm still not sure I understand it.
A recent study by the Texas Transportation Institute at Texas A&M University and other consultants identified 55 at-grade crossings -- intersections where the tracks are at the same level as the roadway -- as candidates for overpasses.
The cost of grade-separating all 55 crossings was projected at $808 million. Most of that would come from taxpayers.
But the benefits of building those overpasses would amount to only $730 million, according to a complex series of calculations that assign a cash value to things such as lost productivity because of traffic delays and tailpipe emissions from idling cars. And those benefits would be spread over 20 years.
In fact, only 13 of those crossings would qualify for the improvements strictly on the basis of a benefit-to-cost analysis, according to the TTI study, which was performed for the Texas Department of Transportation.
The study also identified another 63 crossings as candidates for closure.
The total cost of closing those was put at $5.2 million, a fraction of the $98 million in benefits the study says would result.
Joe Leleikis, a consultant with the engineering firm HTNB in Austin, presented the study to the board of the newly formed Gulf Coast Freight Rail District last month.
Leleikis called the study's findings "a start in the conversation" as the local freight rail district seeks ways for rail and road traffic to coexist more safely and conveniently.
Leleikis said the study focused on motorists using the crossings and the effects of emissions from their vehicles. It did not consider possible noise or neighborhood access problems from closing a crossing or building an overpass.
To calculate benefits, the study looked at costs an overpass or closure would eliminate. Those costs include delays for motorists waiting for a train to pass, the resulting emissions, the fuel wasted by idling engines and the costs to motorists involved in collisions.
That number then was compared with estimated construction costs of the proposed improvement.
Those who have waited for a train to pass on Westheimer near the upscale Highland Village shopping area may be interested to learn that crossing ranked only 38th in ratio of benefits to cost from adding an overpass.
The projected benefit -- $18 million over 20 years -- exceeded those for 23 crossings that ranked higher on the list. But the projected cost of $63 million, due largely to the adjacent high-value residential and commercial properties, was among the highest.
It was followed by San Felipe, to the north, on the same Union Pacific tracks. Putting an overpass there would cost $31 million but produce a benefit worth $22 million. That was good enough for a rank of 19 in benefit-to-cost ratio.
The two sites where overpasses would yield the highest benefit, the study said, are Gessner at U.S. 90A and Shepherd-Durham near Washington, at $76 million and $72 million respectively.
The two also ranked third and fourth in benefit-cost ratio, trailing only Quitman at Elysian (7.3 to 1) and Scott at McKinney (4.7 to 1).
To me, it's practically a no-brainer to do this. We're talking less than a billion dollars total, which would be spread over several years. That's less than half the cost of the Katy Freeway expansion, and it'll keep traffic moving all over town. I say we need to find a way to make this happen.Posted by Charles Kuffner on October 02, 2007 to Planes, Trains, and Automobiles