CLIMATE NEUTRALITY: EVALUATING BIG TRANSPORTATION PROJECTS



One of the most formidable challenges in climate policy is to design a transportation system  that minimizes the consumption of carbon.  That challenge is compounded when regional and state leaders are the final arbiters of major capital-intensive projects, and the City’s role is to influence and guide rather than make the final decision.

It’s easy and understandable to have a visceral reaction against large transportation projects.  Any big project starts with a strike against it, because of the embedded carbon in construction materials, whereas “travel conservation” and small projects that promote walking and bicycling are the most obviously carbon positive.

But our society, travel patterns, and needs are complicated, and some big projects not only make sense, but are essential to our lives and commerce.  Three principles should guide project evaluations:

  1. We must dramatically reduce the use of fossil fueled vehicles. Fossil fuels will continue to increase in cost and are major contributors to emissions that cause climate change, in production, transport, and use.  Recent events in the Gulf of Mexico underline other adverse impacts of the life cycle of fossil fuels, and at some point these resources will run out.
  2. The best long-range strategy is to create compact urban communities that are attractive to people and businesses.  We know that population and economic activity will grow.  New development should link housing and jobs by transit, bike, and pedestrian facilities .  It must also be livable and desirable  – public safety, schools, and parks are climate positive essentials.
  3. We must reduce vehicle miles per capita; but we must plan for vehicle movement, especially to link the jobs and housing in urban centers.  Extensive road structures will continue to be required because vehicles will still be in use.  The “zerocarbonbritain2030” project, for example, achieves zero net emissions by reducing personal trips by car from the current 80% share to 54%, electrifying all private vehicles using renewable resources, and employing hydrogen and biofuels for heavy vehicles that require liquid hydrocarbons http://www.zerocarbonbritain.com/

Core strategies for major transportation investments that reduce carbon emissions should be to:

  • ensure mobility through and between major job and housing centers;
  • emphasize transit and bicycle/pedestrian connections; and
  • provide efficient vehicle capacity but avoid capacity increases.

These are the strategies that have guided Seattle’s work on major transportation projects.  We have made extraordinary strides over the last ten years in ensuring that regional projects move in the right direction.  Projects have been scaled to give transit and bicycle/pedestrian access priority, and to make them integral to the project’s design.  Here’s an over view of the four big projects and how they measure up:

University Link Light Rail, connecting downtown to the University and then north into Snohomish County.  Benefits:  serves major centers along a ten mile corridor with future development opportunities using high-capacity transit.  Notes:  There is a 3-mile gap between Capitol Hill and University stations because of low density; extension to Lynnwood could serve Snohomish County sprawl, need work to develop housing and jobs at stations.

Rebuilding SR 520 between I-5 and I-405.  Benefits:  critical 2nd connection across Lake Washington between west and east side urban areas; new design adds no SOV capacity, supports transit with HOV/bus lanes; designed for future light rail; adds bicycle/pedestrian path across lake; Westside interchange design helps north-south Seattle transit traffic.  Notes:  design details are critical for transit operations; no opportunities for density in immediate vicinity of corridor; Eastside legislators and city officials deserve great credit for willingness to back away from original 8-lane highway proposal.

Eastside Link Light Rail connecting Seattle across Lake Washington to Bellevue and Redmond. Benefits:  light rail connection between west and east side urban areas, critical transit corridor.  Notes:  parking garages and extension into Redmond may support sprawl and driving to light rail; need for systematic urban development strategy along line.

Replacing Alaskan Way Aerial Viaduct through downtown Seattle with Bored Tunnel.  Benefits:  serves north-south corridor of urban density; reduces vehicle lanes from 6 to 4; includes new park, bicycle/pedestrian facilities on waterfront and park amenity for downtown; promotes downtown transit by removing traffic from downtown streets.  Notes:  costs not conclusively known until contracts are signed; portals must be integrated into urban design; transit components not yet funded; tolling must be designed to manage impacts on downtown streets.

Seattle’s representatives have worked successfully with the region and state to make these projects fit into the urban environment and to bring transit and bicycle/pedestrian elements into the forefront.  None of them increases capacity for single occupancy vehicles, and all are consistent with a strategy for reducing vehicle miles traveled per capita.  They provide transportation choices for people and freight between urban centers and contribute to implementing a successful growth management strategy.  Project benefits are likely to be greater than the costs in embedded carbon, especially as the new infrastructure should last for between 50 and 100 years.

Ten years ago Sound Transit was on the ropes, beleaguered in its attempts to complete its first light rail line.  The 520 bridge was projected to double in size, from 4 to 8 lanes, with no dedicated capacity for transit.  The viaduct was going to continue to be a safety risk and blight Seattle’s waterfront.  All that has changed – for the better.

Seattle’s own investments in bicycle and pedestrian facilities and usable streets have contributed to a better city environment.  Our contribution to the regional dialogue has moved this area into a transportation strategy that works and a carbon reduction strategy for the future.  Big transportation projects can contribute to sprawl and increasing automobile use.  Thanks to our successful partnerships, these big projects are moving in the right direction instead.