Knoxville Regional Travel Demand Model Upgrade Program May 6, 2004 Knoxville Regional Travel Demand Model Upgrade Program May 6, 2004

Agenda  TAZ Database  External Trips  Roadway Network  Network Editing Tools  Speed Capacity Estimation  Signal Impedance  Model Interface  Trip Generation  Trip Distribution  Vehicle Occupancy & Time of Day  Traffic Assignment  Resolution of Calibration Issues & Final Validation Statistics  Post-Processing

Expanded Study Area

Traffic Analysis Zones  Total of 747 TAZ  717 Internal zones  30 External zones  45 Data Attributes  Demographic data from Census 2000  Employment by 10 major industry classes  University student enrollment & residence  K-12 th grade enrollments

External Trips  30 External Stations  34,000 daily trips  Five Interstates  Average 25.2% through  21 Other Stations  Average 1.2% through

External Trips (Cont’d)

Roadway Network Multi-scenario Network  Master input network  Over 140 attributes fields containing reference data  Eighteen scenario-specific modeling fields to simplify the development and testing of different network assumptions  Network editing tools  Tools for developing and managing network scenarios  Tools to simplify the coding of traffic signal attributes  Output network  Over 170 attribute fields with detailed outputs from the travel model and post-processors

Roadway Network Master Network  Wealth of reference data  All MINUTP model attributes  Geographic & operational characteristics from TRIMS  Observed speeds from congestion management studies  Scenario-specific assumptions  Number of lanes by direction  Lane and shoulder widths  Presence of median  Posted speed  Access control  Area type  Traffic signalization, priority, and synchronization

Roadway Network Output Networks  Scenario geometric and operational assumptions  Estimated free-flow speeds and capacities  Loaded traffic volumes by direction and time-of-day  Segment VMT & VHT by mode  Average congested speeds by time- of-day  Level of Service  Peak 15 minute speeds and flow densities  VOC, CO, NOx Emissions

Network Editing Tools Scenario Tools  List Scenarios  Add Scenario  Delete Scenario  Copy Projects

Network Editing Tools Signal Tools  Update Signal Fields  Add Signals  Delete Signals  Import Signals from GIS Layer

Speed & Capacity Estimation  Free-flow speeds developed from extensive speed survey data  Capacity estimation based on the Highway Capacity Manual 2000 methodologies  Facility type = f (number of lanes, access control, presence of median, directionality, area type)  Free-flow speed = f (facility type, posted speed)  Capacity = f (facility type, number of signals, approach priority, signal synchronization, lane width, shoulder width, % heavy vehicle, directional distribution)

Speed & Capacity Estimation

Signal Impedance HCM 2000 procedure  Delay/veh = uniform delay * PF + incremental delay + initial queue delay where, PF = progression factor = f (arrival type, g/C) uniform delay =  Varying g/C’s based on approach priority (higher, equal to, or lower than cross street  0.60, 0.50, 0.40 g/C)  Varying arrival types based on signal synchronization (isolated signal vs. series of signals)  Default cycle lengths = 90 sec.

Model Interface

Trip Generation  Six internal auto trip purposes:  HBW, HBS, HBU, HBO, NHBW & NHBO  Trip production and attraction rates for auto mode developed from 2000 Knoxville Household Travel Behavior Study  Trip production: Predictive variables determined by non-parametric correlation analysis Cross-classification table dimension developed by ANOVA  Trip attraction: Multivariate regression techniques  Special university trip generation components for UT based on 1999 IU travel behavior study (both dorm based and commuter)  Special tourist trip generation for southern Sevier County

Trip Generation (Cont’d) Trip Purpose1 st Predictor2 nd PredictorTrip Rate HBWWorkers/H.H.Vehicles/H.H.1.21 HBSStudents/H.H.None0.61 HBUUniversity Student/TAZ None0.15 HBOHousehold SizeVehicles/H.H.3.49 NHBWWorkers/H.H.Household Income0.80 NHBOHousehold SizeVehicles/H.H.1.87 Total7.42 Trip Production Model

Trip Generation (Cont’d) Trip Purpose Independent Variable Parameter Trip Purpose Independent Variable Parameter HBWTotal Employment NHBO Households HBSK-12 Enrollment1.7211Retail Employment HBUUniversity Enrollment1.1488Office Employment HBO Population0.6778Gov’t. Employment Retail Employment Trucks Labor Employment Office Employment0.3638Industrial Employment Gov’t. Employment0.6607Retail Employment NHBW (Other) Population0.1758Office Employment Retail Employment Auto Ex/In Total Employment^ Office Employment0.1244Households Gov’t. Employment NHBW (Work) Total Employment Other Employment Trip Attraction Model

Trip Distribution  Six internal trip purposes (HBW, HBS, HBU, HBO, NHBW & NHBO) & E-I trips  Friction Factors from 2000 Knoxville Household Travel Behavior Study (network skims of geocoded trip ends)  Attractions balanced to productions  Doubly-constrained gravity model  Socioeconomic (or K) factors to help balance county-to- county flows and other important interactions

Trip Distribution (Cont’d)

Feedback Loop for the Knoxville Model

Time of Day  AM peak (7:00~9:00), PM peak (3:00~6:00), and Off-peak  Factors for internal auto purposes from the 2000 Knoxville Household Travel Behavior Study  Factors for other purposes from various sources  TOD factors to split the 24-hr trip table into tables by TOD  TOD factors by trip purpose  Directional factors to convert trip tables in a production- attraction format to origin-destination tables  Directional factors by trip purpose and by TOD

Time of Day (Cont’d)

Time of Day & Directional Factors

Mode Share Private Auto Mode Share by Purpose (from HH Survey)

Vehicle Occupancy AMPMOFF HBW HBS HBU 1.22 HBO NHBW NHBO Vehicle Occupancy by Purpose by Time of Day (from HH Survey)

Traffic Assignment  Time-of-day assignments (i.e., separate AM-peak, PM-peak & Off- peak assignments)  Directional flows by time-of-day  User equilibrium assignment by mode with trucks preloaded  Calibrated volume-delay functions by functional class and signalization

Traffic Assignment (Cont’d) Final Validated Assignment

Resolution of Calibration Issues Issue:Global Under-Loading Solution: ODOT Factors for Trip Under-reporting - from GPS validation of household travel surveys

Resolution of Calibration Issues Issue:Southern Sevier County Under-Loading Solution: Special Tourist Trip Generation  Data on Tourism from National Park Service & Sevier County Economic Development Council  ITE Trip Generation Rates for Occupied Hotel Rooms (8.17/day)

Resolution of Calibration Issues Issue:I-40 East Over-Loading Solution: Special Morristown External Attractions  Data on inter-county flows from CTPP journey to work data  Convert external- internal trip productions to HBW & HBO attractions

Resolution of Calibration Issues Issue:Over-Loading High Class Facilities & Under-Loading Low Class Facilities Solution: Calibrated Volume-Delay Function Parameters

Resolution of Calibration Issues Issue:Unbalanced Interactions between Area Types and with External Stations Solution: Socioeconomic (K) Factors Average K Factors

Final Validation Results  All the MDOT error criteria were met  Final Global Average Loading Error: -1.68%  Final Global VMT Error: -0.15%  Final Root Mean Square Error: 31.96%

Final Validation Results Model Performance by Volume Group

Final Validation Results Model Performance by Functional Class

Final Validation Results Model Performance by Major Corridor

Final Validation Results Model Performance by Screenline, Area Type, & County

Post-Processing  POST_ALT  Average Congested Speeds  Level of Service  Traffic Statistics Report  AQ_PLuS  Emissions by Roadway Segment  County Total Emissions Report  CAL_REP  Calibration Statistics

POST_ALT: Average Speeds  Average congested speeds by time of day were validated against observed speed data from Congestion Management Studies  32.77% RMSE for AM Speeds  33.69% RMSE for PM Speeds  27.98% RMSE for Off Peak Speeds

POST_ALT: Level of Service  Level of Service based on Highway Capacity Manual 2000 criteria by facility type:  Flow-Density for freeways, expressways, & multilane divided highways  Percent “time spent following” & speed decay for rural two-lane highways  Speed decay for urban streets

POST_ALT: Traffic Statistics Traffic statistics by functional class, area type, county, and corridor - including user-defined corridors:

AQ_PLuS: Link Emissions Link-Specific Emissions  Volatile Organic Compounds  Carbon Monoxide  Oxides of Nitrogen in grams/day

AQ_PLuS: County Conformity Emissions summaries by county to facilitate conformity determinations Air Quality Conformity Analysis Report for Knoxville Region from MOBILE6 and the Knoxville Regional Travel Demand Model Mon Mar 29 02:08: Year: 2000 Scenario: TestAQ VMT in Knox County VOC CO NOx Scenario: tons/day tons/day tons/day

Knoxville Transit Analysis Tool Regression Model  Predicts riders per service hour for a route  Using  Population density  Mean household income  Average household workers per household vehicles  Retail employment density of the area within a quarter mile of the route

THANK YOU!