Presented to 2017 TRB Planning Applications Conference Accounting for AV/CV in Long-Range Plans Using Current Travel Demand Models Presented to 2017 TRB Planning Applications Conference
The Question Why are we investing billion$ in capital projects when we are about to encounter a transformative event in how we travel? Automation Transportation Jobs
Background 25 MPO’s 13 TMAs 12 Non-TMAs
Background Traffic Three urban areas in top 12 most congested urban areas (TTI Report) Houston, Dallas, Austin Austin has worst congested roadway in Texas
Background Models 1 ABM model 24 Trip-based models 4 study areas with full mode choice Handful with mode shares Majority are 3- step with direct vehicle generation
Background Forecasting AV/CV demand 4th task in larger research supported by TxDOT How does one measure the potential impacts across the state? Consistent guidance, approaches and measurable outcomes desired by TxDOT
Assumptions 100% vehicle mix Fully autonomous and connected Consistent with NHTSA Level 4 definition Current household auto ownership levels maintained Relinquish navigation, or Participate in shared-rides (albeit limited)
Assumptions Vision of greater ride-sharing Carpooling in tours “Robo-Taxis” Difficult to predict acceptance or system Therefore: Shared-ride splits are held constant, or Proportionally adjusted based on existing forecasted mode shares
Assumptions VMT of unoccupied “robo-taxis” not accounted for in study All sectors in urban area treated equally Restrict travel within downtown, for example Existing external splits held constant
Identifying A Study Area Enumerating demand or system changes, although possible, magnitude of changes may be limited in a majority of MPOs in the State of Texas Limited appreciable system-wide congestion Limited transit ridership (no mode choice model) Narrow peak periods and/or spot congestion
Study Area Austin, Texas (CAMPO) Six-county study area System-wide congestion Most-congested roadway in Texas Extreme peaks Transit component
Study Area Austin, Texas (CAMPO) Population growth 64% (2010 to 2040) Source: Texas State Data Center
CAMPO TDM 4-Step travel model Similar trip generation and distribution models to TxDOT (Texas Package) Mode choice model Nested-logit model (auto, transit, non-motorized) 15-trip purposes Generalized-cost assignment Develop Input Files Initialization Trip Generation Trip Distribution Mode Choice Trip Tables Trip Assignment Model Reports Feedback Source: CAMPO TDM Validation Report
Identifying Scenarios Balance between reasonable assumptions and optimistic enthusiasm Fleet turnover Shared rides Greater mobility for different cohorts (e.g., age & disabled) .... Uncertainty Arguments and counter-arguments
Identifying Scenarios “Typical” items that could be given consideration TDM & AV/CV Land Use Freight External Travel Trip Length Trip Generation Mode Choice Routes Time Choices Network Capacity Costs Utility of Travel
Identifying Scenarios Unintended consequences & outcomes TDM & AV/CV Land Use Freight External Travel Trip Length Trip Generation Mode Choice Routes Time Choices Network Capacity Costs Utility of Travel Land Use Household Location Retail Scope and Location Education Primary & Secondary Workplace Location Freight Distribution
Scenarios Scenarios S1 S2 S3 S4 S5 S6 2040 MTP Forecast “Base” Scenarios S1 S2 S3 S4 S5 S6 2040 MTP Forecast Limited increase in EXPWY and FRWY capacity Increase per hour per lane capacity of FRWY links Increase arterial capacity by 10% Proportionally move transit trips to SOV and HOV (2 & 3+) trip tables Proportionally move transit trips to SOV only trip table Proportionally move transit trips to HOV trip tables. Sequential & cumulative results
TDM Scenario Assumptions Study limited to system & choice Model inputs held constant: Demographics Household and workplace location Trip rates External forecasts Trip lengths Observed data non-existent Imposing assumptions TDM Choice System Demand
Scenario Results AM period results only VMT Speeds Travel Time Delay VMT per person Average trip lengths in minutes and miles Modes
Scenario VMT Results Scenarios Base S1 S2 S3 S4 S5 S6 AON 16,795,034 17,187,458 17,947,172 17,993,762 18,112,750 18,124,662 18,055,190 18,270,971
Scenario VMT Results
Scenario VMT Results 2040 MTP Results “Base” 2040 Scenario 3
Scenario Speed Results
Scenario Speed & VMT Results
Scenario Delay Results
Scenario per Person VMT & Delay Results
Scenario Avg. Trip Length Results
Scenario Avg. Trip Length Results
General Scenario Results Metric Trend Vehicle Miles of Travel (VMT) Region Per Person Travel Time Travel in Uncongested Conditions Travel in Congested Conditions Congested Weighted Speeds Delay Average Trip Length Minutes Miles Mode Shares (Transit)
Where Are We Now? Limited acceptance of placing AV/CV scenario in current plans Curiosity Not yet tangible Leadership and guidance needed to develop consistent approaches and metrics
Special Thanks Wade Odell (TxDOT Project Manager) Hao Pang (TTI) Tom Williams (TTI)
Questions?