HighLight Heading
June 2002
Corridors: a better way to measure impacts?
From Canada to Brazil, transportation planners are looking beyond individual roadways and thinking in terms of transportation corridors. In addition to a highway, a corridor may include alternate modes like rail, dedicated bus lanes, and bicycle or pedestrian paths. Corridor management strives to improve efficiency by encouraging the use of multiple modes to address different transportation needs.
Mn/DOT's Jim Dustrude gave an overview of mode shift incentives—strategies that encourage drivers to use alternative forms of transportation along a corridor. The I-394 corridor in Minneapolis, he said, could see significant benefits from increases in HOV and express bus use—but drivers are notoriously hard to convince.
Dustrude said that, based on his research, drivers might choose alternate modes if they believed they would enjoy better driving conditions (fewer traffic jams, faster commutes) when they did drive. But this type of incentive would require drivers to start taking the bus before any benefits to traffic flow become apparent, a leap of faith they may not be willing to make.
Ken Kriz of the Hubert H. Humphrey Institute of Public Affairs then tackled the difficult issue of benchmarking for urban transportation corridor development. He drew on examples including Denver's T-REX Project and San Diego's I-15 corridor as well as projects in Ottawa and Sao Paulo, Brazil to highlight the many components that go into a successful transportation corridor planning model.
To complicate matters further, Kriz said, complicated state and local funding restrictions require planners to sell voters on public works project plans. This battle for funding can make or break a corridor-management plan before a single section of light-rail track is laid down.
Given the complexity of planning and executing corridor management, geographic information systems (GIS) is becoming an essential tool for determining impacts. Bob Rogers and Brad Digre of Short Elliot Hendrickson, Inc., recounted their experiences in preparing a land use and secondary/cumulative impact analysis for trunk highway 169 near the shores of Mille Lacs Lake in Mn/DOT District 3. Even though existing data sets for the area left much to be desired, the analysis and mapping functions of GIS proved essential to identifying unexpected consequences of corridor development.