Travel Demand Modeling Applications How Modeling is Being Used to Address the Big Issues of Transportation Planning

Transcription

1 How Modeling is Being Used to Address the Big Issues of Transportation Planning Presented by: Dean Munn The Corradino Group

2 Topics This Presentation is organized around two main topics: What is a travel demand model? A review of how models been adapted to address the big issues of transportation planning

3 What is the Purpose of a Travel Model? A tool to predict: Travel patterns Amount of road traffic and transit ridership Performance of the transportation system In response to changes in: Regional development Demographics Infrastructure/services By applying: The latest knowledge and methodologies Detailed local data

4 Model Components Traditional 4 Step Modeling Process 1. Trip Generation 2. Trip Distribution 3. Mode Choice 4. Traffic Assignment These are usually calibrated to local conditions Often a survey of local households is used The model simply applies what we know about local travel behavior in a systematic way

5 Addressing Planning Issues Selected Applications Traffic congestion & development Impacts Air quality and global warming Freight movement Rising fuel costs Measuring effects of land use and urban design Alternative transportation modes Infrastructure finance Economic impacts

6 Traffic Analysis Predicted traffic volumes Growth rates Turning movements Performance Used in corridor studies Used to develop transportation plans Addressing Planning Issues Traffic Analysis & Development Impacts

7 Addressing Planning Issues Traffic Analysis & Development Impacts Traffic Analysis System-wide Performance Measures: Such as Commute Patterns Predicted traffic volumes Growth rates Turning movements Performance Used in corridor studies Used to develop transportation plans Work Trip Mode Split AMBAG Region 2025 Transit 0.86% Auto, 3 Persons 1.48% Walk/Bicycle 6.12% Auto, 2 Persons 16.07% Auto, Drive Alone 75.47%

8 Addressing Planning Issues Traffic Analysis & Development Impacts Modeling Regional Development Impacts

9 Addressing Planning Issues Traffic Analysis & Development Impacts Modeling Local Development Impacts

10 Addressing Planning Issues Federal air quality regulations require transportation plans to show conformity with emissions standards Travel models are used to develop emissions forecasts Strong emphasis on predicting vehicle speeds Some areas are interested in greenhouse gas reductions Air Quality Vehicle Hours of Travel, Delay and Average Speed by Time of Day 2000 AMBAG Region Santa Cruz Monterey San Benito Units AM Peak Total 10,633 13,238 1,679 25,550 Vehicle Hours Delay 1, ,106 Vehicle Hours Percent Delay 10.0% 0.3% 0.3% 4.3% Percent Average Vehicle Speed Miles Per Hour PM Peak Total 12,335 18,934 2,252 33,520 Vehicle Hours Delay ,420 Vehicle Hours Percent Delay 8.0% 2.0% 2.5% 4.2% Percent Average Vehicle Speed Miles Per Hour Off Peak Total 99, ,709 21, ,306 Vehicle Hours Delay 2, ,776 Vehicle Hours Percent Delay 2.6% 0.4% 2.5% 1.3% Percent Average Vehicle Speed Miles Per Hour Daily Total 122, ,881 25, ,377 Vehicle Hours Delay 4,599 1, ,302 Vehicle Hours Percent Delay 3.8% 0.6% 2.3% 1.8% Percent Average Vehicle Speed Miles Per Hour

11 Urban Interstate Addressing Planning Issues Air Quality Speed Prediction Alpha Beta R-squared RMSE BPR % Conical % Akcelik 1.11E % J T Observed Traffic BPR Function Conical Function Akcelik Function Speed Density Ratio

12 250, , ,000 Addressing Planning Issues Freight Movement There is a great deal of interest in freight Communities need good infrastructure to facilitate participation in the global economy Annual Value Shipped in the Greater Detroit Region Models can be used to evaluate freight investments 100,000 50, Transp 36 Electric 35 Machin 28 Chemic 20 Food 33 Primary 34 Fabrica 29 Petrole Inbound 226, ,452 79,689 63,369 72,810 55,361 38,053 34,601 33,448 14, ,447 Outbound 243,036 44,040 67,046 54,856 34,030 31,246 34,312 30,475 23,042 26,198 99,495 Value ($millions) by Commodity 30 Rubber 26 Pulp, paper, All Other

13 Transportation user costs are growing rapidly Travel behavior data shows a response reduced VMT Addressing Planning Issues Rising Fuel Costs mode shifts vehicle purchase decisions Total Auto Operating Costs (Derived from AAA Annual Driving Cost Estimates, Constant $1990) household location decisions Models can only directly address the mode choice side There are opportunities to add model sensitivity (destination choice) Cents per Mile y = x R 2 = Most transportation planning ignores this issue! Year

14 5D Tools Addressing Planning Issues Land Use and Urban Design Intended for Blueprint Planning/General Plan applications, but with some specific plan options Designed to be applied at TAZ level, and will produce jurisdiction summaries Must estimate Vehicle Trip and Vehicle Mile changes due to changes in 5D variables Outputs to be used to estimate GHG changes

15 Addressing Planning Issues Land Use and Urban Design 5D Variables: AMBAG Implementation 5D Elements Variables Data Source Units Density DENS1 DENS2 Households Densiity Employment Density No. Households from TAZ data TAZ land area in sq.mi households per sq. mi. No. of Jobs from TAZ data TAZ land area in sq.mi jobs per sq.mi. Diversity DIVERS Jobs/Housing Ratio No. of Jobs within 1 mile radius No. Households within 1 mile radius Jobs per household ratio Design DESGN1 Walkability Pct. Of TAZ streets that are walkable DESGN2 Average Blockface (miles) Centerline miles of road (nonfreeway) DESGN3 Street Density Centerline miles of road (nonfreeway) Number of links (non-freeway) Land area of TAZ miles walkable per total centerline miles Miles per link road miles/square mile Destinations DEST1 Commercial establishments within 10 min walk Selection set of commercial parcels Count parcels within mi Number of establishments DEST2 Retail jobs within 10 min walk No. of Retail jobs from TAZ data Count jobs within mi Number of retail jobs Distance to Transit DTT1 Street Coverage within 10min. Walk to Transit Stop Street miles within a 10 min walk of transit stops How Modeling DTT2 is Being Access Used to destinations to Address the via transit Big Issues of Transportation Number Planning of stops within 5 miles via transit Pct. Of Centerline Miles Number of stops

16 Addressing Planning Issues Land Use and Urban Design

17 5D Tools Is observed travel behavior related to urban design? Used 2009 NHTS to test Addressing Planning Issues Land Use and Urban Design Vehicle Trip Elasticity by 5D Variable 5D Variable Household Survey t Stat ANOVA (P value) Density Density Diversity Design Design Design Destinations Destinations DistancetoTransit DistancetoTransit Found relationships between our variables and actual travel behavior Translated into elasticities and applied to the model VMT Elasticity by 5D Variable 5D Variable Household Survey t Stat ANOVA (P value) Density Density Diversity Design Design Design Destinations Destinations DistancetoTransit DistancetoTransit

18 Growing emphasis on transit projects Models are used to predict the effects of new services Interest in assessing Nonmotorized travel as well Most funding sources (New Starts, etc.) require a rigorous technical analysis Addressing Planning Issues Alternative Transportation Modes

19 Addressing Planning Issues Infrastructure Finance Revenues are not keeping pace Gas taxes are the current foundation, but are not sustainable (fixed cents per gallon, more efficient vehicles, VMT is flattening) Alternative financing sources Tolls (via traditional public sector or P3) VMT Taxes Others Modeling is used to predict outcomes

20 Addressing Planning Issues Economics Project Feasibility Performance Measures for Decision Making Measure: Crossing Delay Reduction Traffic Volumes VHT Reduction VMT Reduction Congested VMT Reduction Purpose in Alternative Evaluation: Measures immediate local benefits Measures diversion effects local benefits & impacts Measures community-wide diversion effects and potential benefits & impacts Component of travel time savings Component of operating cost savings Component of safety cost savings Comparison of Alternatives Decision Making: Local Impacts Benefit Cost Analysis Annual Benefit ($ Thousands) $3,500 $3,000 $2,500 $2,000 $1,500 $1,000 $500 $ Safety Cost Savings $142 $61 $53 $34 $43 $83 $127 $170 $125 $169 $66 $98 Operating Cost Savings $641 $306 $254 $153 $209 $339 $534 $678 $489 $640 $333 $508 Time Savings $791 $305 $579 $445 $731 $1,294 $1,324 $1,893 $1,684 $2,228 $462 $832

21 Addressing Planning Issues Economics Impacts on State s Economy

22 Summary Models have adapted to address the most important issues Models can be complex and even expensive, but have an important role to play in transportation planning If used correctly, models can add value to many planning applications