Gravity model 3 1 2 4 5 Where do the trips produced in TAZ 3 go? ? ? ? ?
Gravity model equation Forecasted flows between zone i and zone j =Trips attracted to TAZ i Attractiveness of “from” taz Attractiveness of all tazes where, Trips ij : trips between TAZs i and j, Productions i : the productions from TAZ i, Attractions j : the attractions to TAZ j, Friction factor (FF ij ): friction factor for TAZs i and j, Socioeconomic factor (K ij ): socioeconomic adjustment factor for TAZs i and j, i: production TAZ i: attraction TAZ Relative attractiveness Attraction constrained
Conventional urban travel forecasting process Includes four technical phases – Collection of data – Analysis of data – Forecasts of activity and travel – Evaluation of alternatives
Trip generation Trip distribution Mode split Trip assignment Travel demand forecasting – the four step model Estimating the kinds of trips generated Distributing the generated trips in space deciding how trips are made in terms of modes Deciding the routes taken by the trips
MPO: Metropolitan Planning Organization A transportation policy-making organization made of representatives from local government and transportation authorities
Five core functions of MPO Establish a setting Evaluate alternatives Maintain a long-range plan Develop a short-range plan Involve the public
Products produced by MPOs Time/horizonContentsUpdate requirements UPWP1-2 yearsPlanning studies and tasks Annually PLAN25 yearsFuture goals, strategies and projects Every 5 years TIP3 yearsTransportation improvements Every 2 years
Key decisions in long-range planning 1.Approve scope of LRTP process 2.Approve vision and goals 3.Approve evaluation criteria, methods and measures 4.Approve transportation deficiencies 5.Approve financial assumptions 6.Approve strategies 7.Approve plan scenarios 8.Adopt preferred plan scenario 9.Adopt finding of conformity by MPO 10.Adopt LRTP by MPO 11.Approve conformity analysis
Conformity Transportation investments must conform to the state implementation plan (SIP) for meeting air quality standards. Conformity is a way to ensure that Federal funding and approval are given to those transportation activities that are consistent with air quality goals.
Transportation Conformity Process SIP Emission budget TCMs State Conformity procedure Transportation plan Perform regional analysis for plan Compare build vs. no build Emission budget Timely implementation of TCMs Plan conformity STP Revision needed Yes No Yes or TIP Plan Revision needed Perform regional analysis for plan Compare build vs. no-build Emission budget Timely implementation of TCMs TIP conformity Project Hot Spot analysis Project summary Project approval TIP Revision needed No Yes No Yes
What are subject to conformity? Transportation plans Transportation improvement programs
What is the frequency of conformity determination?
Options to reduce emissions from vehicles Vehicle controls Fuel-based standards Inspection and maintenance programs Transportation control measures Market-based Transportation Control Measures
A multi-modal program includes: Land use management (examples only) – Planning and zoning – Phasing and adequacy – Urban design – Mixed use – Density Demand management (examples only) – Alternative work schedule – Pricing – Alternative modes – Alternative work locations – Employer support programs
A multi-modal program includes: Supply management – Intelligent transportation system – Transit facilities and services – Intermodal facilities – Traffic engineering – Highway capacity and bike/walkways
Other acronyms LULU: locally unwanted land use NIMTOO: not in my term of office BANANA: build absolutely nothing anywhere near anyone NOPE: not on planet earth CAVES: citizens against virtually anything