Waterbuffalo
07-21-2008, 07:22 PM
http://www.portlandtribune.com/news/story.php?story_id=121658836643033600
Jim Redden, PT
Skyrocketing gas prices are credited with helping set new ridership records on the regional transit system. TriMet reports that more people are using its buses and MAX trains every month.
But the most recent Oregon Department of Transportation figures show that motor vehicle traffic is down only slightly on some area freeways.
According to the ODOT figures, daily traffic counts dropped a little less than one-half of 1 percent at three key checkpoints between May 2007 and May 2008.
But even then, only two of the checkpoints reported actual declines. Both were the bridges over the Columbia River between Oregon and Washington.
The figures reveal that traffic counts 1 percent on the Interstate 5 bridge and 2.5 percent on the Interstate 205 bridge between the two years.
But traffic actually increased 1.7 percent at the Northeast 53rd Street overpass on Interstate 84, historically the busiest freeway checkpoint in the state.
The increase dropped the overall decline at all three checkpoints to just 2,306 vehicles out of more than 490,000 a day — a mere 0.47 percent drop.
The differences between the checkpoints also underscores the hazards of generalizing about Portland-area traffic patterns.
“Can we predict with total accuracy what the traffic counts will be next year or even next month?” asked ODOT spokesman Dave Thompson. “No. They vary all the time.”
Nor would Thompson speculate why traffic was up at the I-84 checkpoint and down on the two bridges.
“The department doesn’t get into things like that,” he said.
Bridge models are ‘simply wrong’
The issue is especially important now because of the controversy over the proposed Columbia River Crossing bridge between Portland and Vancouver. Governments in the region — including the Portland City Council and Metro Council — have conditionally endorsed building a replacement I-5 bridge with freeway interchange improvements, a new light-rail line to Vancouver, and improved access for pedestrians and bicyclists. At an estimated $4.2 billion, it would be the most expensive transportation project in the history of the region.
Supporters say such a bridge needed to reduce congestion, both now and over the next 50 years, when the population of the region is expected to double to 3.85 million people, according to Metro projections.
“It is the right bridge at the right time,” said Metro Council Rex Burkholder, who represented the regional government on a bi-state advisory panel that recommended the proposal.
But critics argue that people are already driving less because of higher fuel costs. They also fear that a new bridge will encourage more people to live in Washington and work in Oregon, increasing sprawl and global warming pollution.
“There are good reasons to believe the CRC traffic models are simply wrong about the project’s effects on future congestion,” Portland economist Joe Cortright wrote in an eight-page critique of the project.
Such concerns have prompted some of the critics to push for a scaled-back project. For example, Bob Stacey, executive director of 1000 Friends of Oregon, said his land-use watchdog group would only support a new bridge if it did not increase motor vehicle capacity.
A reversal of trends
The issues raised by the critics are considered so important that most governments involved in the project have asked that they be studied further. But the new ODOT figures suggest that firm answers may be hard to find.
The figures were requested by the Portland Tribune. They were intended to offer a snapshot of regional driving patterns, not a comprehensive analysis of the entire Portland area freeway system. ODOT has yet to release the full set of 2007 figures for all freeways. Those for 2008 will not be released for another year or more.
Nevertheless, Thompson suggests the recent decline may be more significant than it appears. Traffic at all three checkpoints increased substantially between 2003 and 2006, the most recent year for which annual daily figures are available. Any decline — however modest — could signal a reversal of those trends.
“The change could be significant, but we won’t know until we have a full year’s worth of data,” he said.
Even then, year-to-year comparisons are not always accurate, Thompson warned. The figures are generated by vehicles passing over sensors buried in the roadways. But the sensors are occasionally disabled by construction projects, such as those that took place in recent years to widen portions of I-205.
“Without a complete analysis that looks at everything, it’s hard to draw really firm conclusions,” he said.
Jim Redden, PT
Skyrocketing gas prices are credited with helping set new ridership records on the regional transit system. TriMet reports that more people are using its buses and MAX trains every month.
But the most recent Oregon Department of Transportation figures show that motor vehicle traffic is down only slightly on some area freeways.
According to the ODOT figures, daily traffic counts dropped a little less than one-half of 1 percent at three key checkpoints between May 2007 and May 2008.
But even then, only two of the checkpoints reported actual declines. Both were the bridges over the Columbia River between Oregon and Washington.
The figures reveal that traffic counts 1 percent on the Interstate 5 bridge and 2.5 percent on the Interstate 205 bridge between the two years.
But traffic actually increased 1.7 percent at the Northeast 53rd Street overpass on Interstate 84, historically the busiest freeway checkpoint in the state.
The increase dropped the overall decline at all three checkpoints to just 2,306 vehicles out of more than 490,000 a day — a mere 0.47 percent drop.
The differences between the checkpoints also underscores the hazards of generalizing about Portland-area traffic patterns.
“Can we predict with total accuracy what the traffic counts will be next year or even next month?” asked ODOT spokesman Dave Thompson. “No. They vary all the time.”
Nor would Thompson speculate why traffic was up at the I-84 checkpoint and down on the two bridges.
“The department doesn’t get into things like that,” he said.
Bridge models are ‘simply wrong’
The issue is especially important now because of the controversy over the proposed Columbia River Crossing bridge between Portland and Vancouver. Governments in the region — including the Portland City Council and Metro Council — have conditionally endorsed building a replacement I-5 bridge with freeway interchange improvements, a new light-rail line to Vancouver, and improved access for pedestrians and bicyclists. At an estimated $4.2 billion, it would be the most expensive transportation project in the history of the region.
Supporters say such a bridge needed to reduce congestion, both now and over the next 50 years, when the population of the region is expected to double to 3.85 million people, according to Metro projections.
“It is the right bridge at the right time,” said Metro Council Rex Burkholder, who represented the regional government on a bi-state advisory panel that recommended the proposal.
But critics argue that people are already driving less because of higher fuel costs. They also fear that a new bridge will encourage more people to live in Washington and work in Oregon, increasing sprawl and global warming pollution.
“There are good reasons to believe the CRC traffic models are simply wrong about the project’s effects on future congestion,” Portland economist Joe Cortright wrote in an eight-page critique of the project.
Such concerns have prompted some of the critics to push for a scaled-back project. For example, Bob Stacey, executive director of 1000 Friends of Oregon, said his land-use watchdog group would only support a new bridge if it did not increase motor vehicle capacity.
A reversal of trends
The issues raised by the critics are considered so important that most governments involved in the project have asked that they be studied further. But the new ODOT figures suggest that firm answers may be hard to find.
The figures were requested by the Portland Tribune. They were intended to offer a snapshot of regional driving patterns, not a comprehensive analysis of the entire Portland area freeway system. ODOT has yet to release the full set of 2007 figures for all freeways. Those for 2008 will not be released for another year or more.
Nevertheless, Thompson suggests the recent decline may be more significant than it appears. Traffic at all three checkpoints increased substantially between 2003 and 2006, the most recent year for which annual daily figures are available. Any decline — however modest — could signal a reversal of those trends.
“The change could be significant, but we won’t know until we have a full year’s worth of data,” he said.
Even then, year-to-year comparisons are not always accurate, Thompson warned. The figures are generated by vehicles passing over sensors buried in the roadways. But the sensors are occasionally disabled by construction projects, such as those that took place in recent years to widen portions of I-205.
“Without a complete analysis that looks at everything, it’s hard to draw really firm conclusions,” he said.