1、TRANSPORTATION PLANNING,TOPICS,ROADS AND PUBLIC GOODS RATIONALE TO JUSTIFY ROAD BUILDING URBAN PLANNING AND TRAFFIC CONGESTION (UNINTENDED CONSEQUENCES) ROAD BUILDING & MANAGEMENT: THE OLD PARADIGM ROAD BUILDING AND MANAGEMENT: THE NEW PARADIGM MODEL OF URBAN GROWTH AND TRANSPORTATION,TYPE OF GOODS,
2、PRIVATE GOOD Rival Exclusion PURE PUBLIC GOOD OR CPR Jointly consumed or non rivalry non-exclusion TOOL GOODS Jointly consumed or non rivalry Exclusion can occur COLLECTIVE PUBLIC GOODS Jointly consumed or non rivalry up to a limit non-exclusion,Typology of G & S,Individual goods,Toll Goods,consumpt
3、ion,individual,Joint,Feasible Exclusion Infeasible,Common pool goods,Collective goods,Source: E.S. Savas 2000:44-45,Private car Taxi serviceBus service/SubwayTurnpike Highway City street,RATIONALE TO JUSTIFY ROAD BUILDING,URBAN PLANNING AND TRAFFIC CONGESTION,SHORT-TERM CAUSES Population and job gro
4、wth More intensive use of automobile Failure to build more roads Failure to make drivers bear full cost,Source: A. Downs,URBAN PLANNING AND TRAFFIC CONGESTION,LONG-TERM CAUSES Concentration of work and trips in time Disconnection between place of work and residence Low density development (residence
5、 and work) Preference of private vehicle over mass transit system Urban design/ City planning (middle class bias),ACCESS & MOBILITY: THE OLD PARADIGM,Roads are considered public goods Solutions came from the supply side Gasoline tax as a proxy for road pricing To complex to administer and coordinate
6、 efforts among different levels of government Disjoint relationship between land use and travel demand Problems are taught to be linear CONGESTIONBUILD MORE ROADS,ACCESS & MOBILITY: THE NEW PARADIGM,Roads are becoming “toll goods” Solutions are coming from the demand side (ability & willingness to p
7、ay) Price system based on marginal cost Public and private partnership starting to emerge as well as decentralization of decision making Land-use and travel demand are part of the problem as well as the solution (New Urbanism) Problems are seen as circular with feedback loops,A SYSTEM MODEL,LOW DENS
8、ITY DEVELOPMENT,INCREASE TRAVEL MILE PER VEHICLE,INCREASES ROAD DEMAND,PRIVATE TRANSPORTATION,BUILD MORE ROADS,TRANSFORM LAND USE & DENSITY,GENERATES MORE ECONOMIC ACTIVITIES,LAWS OF HUMAN BEHAVIOR,FORECASTING TRAVEL DEMAND,Four step process Estimating trip generation (HH income, # persons in the HH
9、, # vehicles, density) Estimating trip distribution (Gravity model): The force of gravitation between two objects is proportional to the product of their masses and inversely proportional to the square of their distance Estimating modal split (private vs. public modes) Trip assignment (distribution
10、of the trips among alternate routes: e.g. how to get to downtown? ),Census Methodology,Origin 1,000 trips,Destination A 20,000 square feet,Destination C 80,000 square feet,Destination B 70,000 square feet,4 miles,10 miles,8 miles,Census tracks Census blocks,Square feet of office space is a proxy for employment or the mass (attraction) aspect in the model,
