Problem
Evidence suggests that there are synergies between transit, land use, and pricing strategies that enhance the greenhouse gas (GHG) reduction effect of each when implemented together.  However, more detailed information on the magnitude and characteristics of these synergies is not available.  Research in this area would help local and state governments, metropolitan planning organizations, transit agencies, and others estimate the potential GHG reduction impacts of pursuing such strategies in conjunction with one another.
 
Objective
The objective of the research is to examine interactions between transit, land use, and pricing strategies. The types of questions to answer include:

What is the magnitude of the synergistic effects? What are the co-benefits?
What is the impact of pursuing strategies jointly on the cost-effectiveness of the strategies?
What do case studies of metropolitan areas implementing strategies jointly teach us?
How can strategies combine to make travel alternatives competitive with driving?
How can these strategies be best implemented in an economic downturn with tight budgets?
Can pricing strategies cover the costs of transit investments? Who pays and who benefits? How are public agency budgets affected and how are household budgets affected?
What are the operational implications of pursuing transit oriented development without funding available to expand transit service to meet increased demand?
How do different types of transit modes, such as bus, bus-rapid-transit, and rail impact the outcomes from these combined strategies?
Are there thresholds that can be reached at which costs decrease (for instance, levels of regional accessibility at which households can conveniently reduce automobile ownership). At which residential and employment density levels are different types of transit service more cost-effective? 
What variations of strategies are most appropriate for different types of communities?
 
Related Work
·      Cambridge Systematics, Moving Cooler, 2009.
·      TCRP Report 128, Effects of TOD on Housing, Parking, and Travel, 2008.
·      TRB Special Report 298: Driving and the Built Environment
 
Urgency/Priority
Draft transportation reauthorization legislation and climate change legislation being considered in Congress would require states and metropolitan planning organizations to set transportation GHG reduction targets and develop strategies to meet these targets. Solid information on the impacts of combined strategies on reducing transportation GHGs is crucial to the ability to develop these strategies.