1. Centre for Transport Studies Imperial College 1 Congestion Mitigation Strategies: Which Produces the Most Environmental Benefit and/or the Least Environmental Cost? Bob Noland Centre for Transport Studies Imperial College London

2. Centre for Transport Studies Imperial College 2 Overview of presentation Environmental impacts of transport policies Policies often promoted to reduce congestion Some examples of possible environmental effects of alternative policies Attempt to rank by environmental costs/benefits

3. Centre for Transport Studies Imperial College 3 What are the environmental effects of transport? Air quality Climate change Noise Construction impacts Visual / aesthetic impacts Land use change Ecological impacts on wildlife Water quality / run-off Community severance Safety

4. Centre for Transport Studies Imperial College 4 Scale of environmental impacts Global –Climate change Regional –Air quality –Land use –Ecological impacts Localized –Noise –Construction impacts –Visual/aesthetic impacts –Water quality / run-off –Community severance / safety

5. Centre for Transport Studies Imperial College 5 What policies are promoted to reduce vehicle congestion? (1) Network capacity expansion –Road network HOV lanes Signal coordination Incident management –Public transport Capacity reduction –Pedestrianization –Bicycle lanes –Land use / urban design Demand management –(see next slide)

6. Centre for Transport Studies Imperial College 6 What policies are promoted to reduce vehicle congestion? (2) Demand management –Pricing policies Congestion pricing (including HOT lanes, corridor pricing, cordon pricing, area-wide pricing) Parking pricing Fuel taxes VMT fees –Employer-based policies Ridesharing Parking cash-out / transit subsidies Telecommuting / work schedules Policies should not be viewed in isolation as many need to be implemented in combination

7. Centre for Transport Studies Imperial College 7 Environmental effects related to behavioral impacts of policies Capacity expansion –Induced travel –Land use impacts –Changes in speed and driving style Capacity reduction –Economic responses to land use / urban design change Pricing policies –Elasticity of demand –Other travel alternatives available Employer-based policies –Telecommuting behavior –Location of employer and other options available

8. Centre for Transport Studies Imperial College 8 Environmental effects dependent on technology Air quality –Dependent on emission control technology and type of fuels used Climate change –Dependent on fuel efficiency technology and advances in alternative sources of energy Noise –Technologies to reduce engine and tire noise Safety –Vehicle safety technology and advances in medical care procedures –Also dependent on behavioral reactions to safety regulations, for example seat-belt usage

9. Centre for Transport Studies Imperial College 9 Environmental impacts associated with congestion reduction policies Capacity expansion –increase in number of lanes on a congested freeway –construction of rail line along major corridor –signal coordination along arterials, some new lanes Congestion pricing options –Corridor pricing –Cordon pricing –HOT lanes Capacity reduction –pedestrianization –land use / urban design changes Do nothing

10. Centre for Transport Studies Imperial College 10 Ranking of policies? List does not reflect beneficial effect of these policies on congestion reduction or increased mobility Environmentally better –Pedestrianization –Bicycle lanes –Land use / urban design –Telecommuting / work schedules –Parking cash-out / transit subsidies –Incident management –Fuel taxes –VMT fees –Parking pricing Environmentally worse –Congestion pricing: corridor –Congestion pricing: cordon –HOV lanes –HOT lanes –Do nothing –Ridesharing –Increased bus service –Signal coordination –Fixed rail expansion (urban) Environmentally even worse –Fixed rail expansion (suburbs) –Road network expansion