It’s time (drum roll…) for the annual Urban Mobility Report published by the Texas A&M Transportation Institute (TTI). The report provides a detailed illustration of traffic problems in a total of 498 urban areas across the United States and relays a familiar message that traffic congestion is not getting better and lists the usual suspects in the worst offender category: Washington, D.C., Los Angeles, San Francisco-Oakland, New York-Newark and Boston.
What’s really interesting about this report is that they introduce a new metric: the “Planning Time Index” (PTI). The PTI is an attempt to combat what the report says is the biggest problem for motorists in congested areas – the unreliability of commuting time or in plain English from the report: “as bad as traffic jams are, it’s even more frustrating that you can’t depend on traffic jams being consistent from day-to-day.” The report has a succinct explanation of the PTI which I will use:
The Planning Time Index (PTI), a measure of travel reliability, illustrates the amount of extra time needed to arrive on time for higher priority events, such as an airline departure, just-in-time shipments, medical appointments or especially important social commitments. If the PTI for a particular trip is 3.00, a traveler would allow 60 minutes for a trip that typically takes 20 minutes when few cars are on the road. Allowing for a PTI of 3.00 would ensure on-time arrival 19 out of 20 times.
For example the PTI for Washington, D.C. is 5.72, which means that drivers who want to be late only once a month should budget more than an hour and 40 minutes for a trip that takes 20 minutes in light traffic. Whew, I think I’ll just sneak in the back door!
One more new thing this year is that the report estimates the additional carbon dioxide (CO2) emissions attributed to traffic congestion at 56 billion pounds, which is about 380 pounds per auto commuter. A link to the report can be found here. Happy reading!
What’s really interesting about this report is that they introduce a new metric: the “Planning Time Index” (PTI). The PTI is an attempt to combat what the report says is the biggest problem for motorists in congested areas – the unreliability of commuting time or in plain English from the report: “as bad as traffic jams are, it’s even more frustrating that you can’t depend on traffic jams being consistent from day-to-day.” The report has a succinct explanation of the PTI which I will use:
The Planning Time Index (PTI), a measure of travel reliability, illustrates the amount of extra time needed to arrive on time for higher priority events, such as an airline departure, just-in-time shipments, medical appointments or especially important social commitments. If the PTI for a particular trip is 3.00, a traveler would allow 60 minutes for a trip that typically takes 20 minutes when few cars are on the road. Allowing for a PTI of 3.00 would ensure on-time arrival 19 out of 20 times.
For example the PTI for Washington, D.C. is 5.72, which means that drivers who want to be late only once a month should budget more than an hour and 40 minutes for a trip that takes 20 minutes in light traffic. Whew, I think I’ll just sneak in the back door!
One more new thing this year is that the report estimates the additional carbon dioxide (CO2) emissions attributed to traffic congestion at 56 billion pounds, which is about 380 pounds per auto commuter. A link to the report can be found here. Happy reading!
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