National VMT Development Procedure

1. National VMT Development Procedure Highway Information Seminar October 22 - 25, 2012 Patrick Zhang, PE patrick.zhang@dot.gov , 202-366-1941 Office of Highway Policy Information, FHWA

2. Objective To illustrate how national vehicle miles travelled data are developed and the criticalness of State submitted data

3. What National VMT Is About National VMT data are often referred to as VM-1 data because the table has all the information is named VM-1. The National VMT data has four key components: • VMT by roadway functional class and vehicle type • National registered vehicles by six vehicle types, • National total fuel consumed • Fuel efficiency - MPG for each of the six vehicle groups

4. VM-1

5. Data Sources • VMT: Highway Performance Monitoring System (HPMS) from States • Registered Vehicles – from States • Fuel consumption - from States • Fuel efficiency – Modeling

6. VMT HPMS Statewide Summaries for rural collectors and locals. HPMS Urban Summaries AADT x length VM-2 table: VMT by 14 roadway types and by states VMT By 6 roadway types and by 6 vehicle types Merger roadway types + VM-4 table: Vehicle Summary Data by 6 vehicle types and 6 roadway types

7. VM-2 table Vehicle Miles Travelled by Roadway Types Data Sources 1: HPMS Statewide Summaries – daily VMT for rural minor collectors, rural locals, and small urban locals 2: HPMS Urban Area Summaries – urban local daily VMT 3: All Others – AADT x length of roadway segment State total = 1 + 2 + 3

8. Sample VM-2 (portion)

9. VM-4 Table • VM-4 Table is created using Vehicle Summary Data • Vehicle Summary Data contains 6 Vehicle Types and 6 Roadway types • Vehicle Summary Data are in the format of Percentages on each of 6 roadway types • Total of percentages on each roadway is 100%

10. A Sample Vehicle Summary Data

11. Roadway Types Merges • VM-4 VM-2 • Interstate (1) Interstate • Other Arterial  (2) PA - Other Freeways + • (3) PA – Other+ • (4) Minor Arterial • Other Urban (rural)  (5) Major Collector + • (6) Minor Collector+ • (7) Local

12. VMT by Vehicle Calculations Vehicle VMT (on a roadway) = % (on a roadway) * VMT (of a roadway)

13. How to Calculate Vehicle VMT • Vehicle VMT (roadtype) = Veh% x VMT (roadtype) Veh% is the Vehicle Summary Data • Example: • A stable Veh% is essential to produce stable Vehicle VMTs

14. Vehicles • # of vehicle is imported from MV-1 table (include Motorcycles) • 4 Vehicle types are split using Polk data (Light Duty Vehicle short wheel and long wheel base, Single Unit Truck, Combination Truck) • VMT per vehicle is calculated • Fuel consumed per vehicle is calculated

15. New VM-1 Vehicle classification • Light Duty Vehicle Short WB: wheelbases <= 121 inches.    • Light Duty Vehicle Long WB: wheelbases > 121 inches. • Most of car, van, small SVU, mini pickups belong to Light Duty Vehicle Short WB • Large passenger car (0.7%), vans (21.0%), pickup trucks (83.4%), and sport/utility vehicles (8.5%) belong to Light Duty Vehicle Long WB in 2008.

16. Fuel Consumption

17. Fuel Efficiency • Vehicle Stock Model to approximately estimate MPG by vehicle types • Optimization tech to finalize the MPG total fuel = total fuel consumed

18. Stock Model The vehicle stock model can be expressed mathematically as: Where

19. MPG Model Where

20. References Annual Vehicle Miles Travelled and Related Data -- Procedures Used to Derive Data Elements Contained in Highway Statistics Table VM-1 for Years 2009 and after and 2007 and 2008 Historical Data http://www.fhwa.dot.gov/ohim/vm1_methodology_2007.pdf

21. Questions?