Reporting Registered Vehicle Fleet Fuel Efficiency Estimates by Census Block
Corresponding Author: Becky Knudson, Oregon Department of Transportation
Presented By: Becky Knudson, Oregon Department of Transportation
Abstract
Oregon Department of Transportation (ODOT) vehicle registration records were processed and enhanced in order to calculate the average fleet fuel efficiency by Census Block across the state of Oregon. Oregon Metropolitan Planning Organizations (MPOs) wanted to know more about their fleet characteristics, primarily fuel efficiency. ODOT partnered with the Oregon Department of Environmental Quality (DEQ) to assign fuel efficiency factors for registered vehicles using DataOne Vehicle Identification Number (VIN) decoding software. Each vehicle record was geocoded to a Census Block and average fuel efficiency was calculated. Not all records could be geocoded, but they were retained and reported to the MPOs in table form for the region.
This method enabled MPOs to gain valuable fleet information previously unavailable due to confidential record sharing rules. The Oregon passenger vehicle fleet tends to be older than some U.S. states; households hold on to vehicles longer. This has implications related to GHG production, emissions and timely implementation of new vehicle safety features. This approach provided valuable information for planning and public policy analysis, while maintaining personal information confidentiality.
Two software tools were used to process the data. The dataset contained over twelve million vehicle registration records. Selected fields needed to be standardized and prepared for aggregation. The statistical software JMP was used for this process. ArcGis was used to query out currently registered vehicles, geocode the vehicle addresses and aggregate them to Oregon’s 196,550 Census Blocks. This resulted in 3.8 million records. DataOne fields were joined to the GIS records using the VIN.
The federal Payroll and Employment data confidentially criteria were used to meet the goal of confidentiality. That is, at least 3 vehicles had to be in the Block or no more than 80% of Block vehicles could be at one location. Records not meeting these criteria were not mapped, but retained in table form stripped of detail on their physical location. A geodatabase was created for each Oregon County.