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AMPO TRAVEL MODEL WORK GROUP March 20, 2006. BALTIMORE METROPOLITAN COUNCIL MODEL ENHANCEMENTS FOR THE RED LINE PROJECT. BMC Enhanced Model – Background. Update to the Baltimore region travel demand model MTA provided funding Developed by William G. Allen with assistance from BMC staff
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AMPO TRAVEL MODEL WORK GROUP March 20, 2006 BALTIMORE METROPOLITAN COUNCIL MODEL ENHANCEMENTS FOR THE RED LINE PROJECT
BMC Enhanced Model–Background • Update to the Baltimore region travel demand model • MTA provided funding • Developed by William G. Allen with assistance from BMC staff • Motivation/Goal • Revised mode choice model to meet FTA technical analysis of user benefits utilizing SUMMIT • Analysis of proposed Red Line to request New Starts funding • Develop one regional model used for long/short range regional planning, regional conformity analysis, and FTA new starts analysis
BMC Modeling Area BMC Model Area MWCOG Jurisdictions in BMC Model
BMC Enhanced Model–Objectives • User friendly – logical input file names • Reduce off-model data preparation • Reduce number of input files • Incorporation of 2001 NHTS data • Meet Requirements of FTA • Remove “cliff” functions • Use same coefficients for transit and auto time • Eliminate geographic bias constants • Produce input files for SUMMIT
BMC Enhanced Model–Status • Draft functioning model as of February 2006 • Conducting sensitivity test designed to evaluate estimated changes in demand • BMC staff developing a further understanding of the model through application, documentation, and development of user guide/local training session • Extensive quality control checking of all model aspects • Model runs in 9 to 10 hours (previous model 6 to 7 hours)
Trip Generation Features • Demographic models • Households by size (5)/income (4) • Urban Size (Baltimore City, DC, Montgomery, PG) • Suburban Size (All Others) • Urban Income (Baltimore City and DC) • Suburban Income (All Others) • Workers (4)/income (4) • Workers for Washington region must be estimated based on household size and income from PUMS • Income split is 10/15/20/55% of households (lowest to highest)
Trip Generation Features (Cont’d) • 10 trip purposes • Home-Based Work, Shop, Other, and School • Non-Home-Based JTW, JAW, and OBO • Truck CV, MTK, and HTK • Nine area types based on household and employment density • Trip productions by rates for different HH size/income and worker/income combinations • Trip attractions by regression equation, adjusted by area type
Trip Generation Features (Cont’d) • Home-based I-I trip attractions normalized to match productions • Non-home based trip attractions normalized to productions, then productions set equal to attractions • External trip generation based on counts/projections and distance between zone and closest external • X-X trips based on base year trip table • Attraction split model by income
Trip Distribution Features • Composite Time • Highway, transit (2 lowest income classes, HBW, HBS, HBO), toll • Simulated congested time used for HBW, JTW, free-flow time for other purposes during first pass • Two loops of speed feedback for HBW and JTW trips • K-factors replace barrier penalties • Truck deltas applied after distribution • Truck deltas now additive, not multiplicative
Mode Choice Features • New transit access pre-process • TP+, ArcInfo, Microsoft Access • Create up to 9 walk links per mode, unlimited drive links within 30 minutes • Create ½ mile buffer around local transit lines and express bus and rail stops • Identify walk access share of each zone within buffer • Determine average walk time for bus, rail, commuter rail, peak and off-peak • Select links from those actually used in pathbuilding limited in number and distance/time
Mode Choice Features • New nested logit mode choice model • Same structure for all non-school purposes • Model for school trips includes a top-level school bus nest • Parking cost model • Three levels of auto occupancy • Three transit modes • Two access modes
Mode Choice Features (Continued) • Peak and off-peak transit networks • “Freeze-dry” Washington mode choice • Dummy links for DC transit access/egress
Assignment Features • Fixed weights based on future equilibrium assignment • First two feedback loops assign AM peak trips (6:30-9:30 a.m.) • Final assignment for four time periods • AM peak (6:30-9:30 a.m.) • Midday (9:30 a.m.-3:30 p.m.) • PM peak (3:30-6:30 p.m.) • Night (6:30 p.m.-6:30 a.m.
Assignment Features (Continued) • Number of iterations • AM peak = 14 • Midday = 8 • PM peak = 14 • Night =6
Next Steps • Test Alternatives • Run SUMMIT • Continue checking results • Submit to FTA • Document