Carbon Footprint of the U.S. Population: Causes and Spatial-Temporal Pattern: Vehicle Occupancy Midterm Report Class Project MAE/ENV 449, SP 2007 By: Timothy Arde-Acquah, Louis Hsu, and Jason Link Instructor: R. Husar © Liz Leyden 2006

Introduction Purpose  Find vehicle occupancy data (passengers per vehicle) for years , separated by state and vehicle type Approach  Searched numerous websites Major Finding  Overall, most complete set of data was a nationwide compilation spanning from

Results (Timothy)  Introductory - Working Definition: "Vehicle occupancy conceptualized as function of number of people in the vehicle and distance traveled per trip." - 5 Vehicle Occupancy Measurement methods: traditional roadside/windshield observation, carousel observation, photographic surveillance, mail-out or telephone surveys, accident database extraction method.

Results Secondary - Daily Passenger Travel Fig.1-Proportion of Trips by ModeFig.2- Mean Occupants by Trip Purpose

Results/Findings Passenger-Vehicle Occupancy (Summary) * 71.5% of all vehicle trips are made in single-occupant vehicles. *The average passenger-vehicle occupancy for all trip purposes is *The passenger-vehicle occupancy for Home Based Work trips is NOTE: Passenger-vehicle occupancy is calculated by dividing the sum of all passengers (that is, the sum of the modes “Drove Alone,” “Drove with Passenger” and “Rode as Passenger”) by all passenger vehicles (that is, the sum of “Drove Alone” and “Drove with Passenger.”) -Vehicle Occupancy per Vehicle Mile by Time of Day and Weekend Status (Tables available on Class wiki) -Probably useful: How to calculate AVO rates

Results (Jason) Nationwide Personal Transportation Survey (NPTS)  1969  1977  1983  1990  US DOT  FHA Trip Purpose, Trip Length, Household Size, Place of Residence

Vehicle Occupancy by Trip Purpose (1977)

Comparison of Vehicle Occupancies

National Vehicle Occupancy Rates-BTS (Louis) Source:

Cross Checking Data NPTS Values Compared with BTS Data NPTS BTS average value (with motorcycle)BTS passenger car BTS other 2 axle, 4 wheel

Further Research Find comprehensive vehicle occupancy data from , broken down by  State  Vehicle type