Vehicle mileage by county

Highway Loss Data Institute Bulletin Vol. 32, No. 28 : December 2015 Vehicle mileage by county Executive summary Earlier studies by the Highway Loss Data Institute (HLDI) found a strong correlation between average miles per day (MPD) and collision claim frequency. Average MPD was shown to vary significantly by region and by county within a metropolitan area. This study updates an earlier study on vehicle mileage by county. The mileage information was available through a cooperative agreement with CARFAX. CARFAX is a unit of IHS Inc. and provides vehicle history reports. The map below shows average MPD in the United States by county. The Northeast, south Florida, and West Coast predominately had low average MPD. This may be due to more urban areas, greater use of public transportation, or higher percentages of retirees. Counties with the lowest average MPD were islands, isolated areas in Alaska, and urban centers of large metropolitan areas. High average MPD counties were primarily located in the Southern states between Texas and South Carolina, in the outer suburbs of Richmond, Virginia and Minneapolis, Minnesota and in some rural counties containing a federal Indian reservation. Counties with the highest average miles per day were mainly in rural areas where long distances to work or shopping may be typical. by county, 2005 14 models

Introduction An earlier HLDI study found that average mileage varied significantly by region and by county within a metropolitan area (HLDI 2010 Vol.27, No.3). Average mileage was highest in the South and lowest in the Northeast, West Coast, and south Florida. In metropolitan areas, urban central counties had lower mileage than the outer suburban counties. The effect of higher mileage has been shown to increase collision claim frequency (HLDI 2010 Vol.27, No.13). Methods The linking of mileage data and HLDI insurance data was possible through a cooperative agreement with CARFAX. Vehicle identification numbers (VINs) from the HLDI database were matched to odometer readings from CARFAX. Odometer readings came from multiple sources including title transfers, yearly inspections, and routine maintenance service. The frequency of odometer readings varied widely. Some vehicles had just one or two odometer readings, while others had numerous records (e.g. every oil change and state inspection). MPD was computed by taking the ratio of the increase in miles from two consecutive odometer readings to the number of days between the two readings. Only data that could be matched to collision coverage in the HLDI database were used. The current study examined vehicle mileage data by geographic area. The county assigned to a VIN represents the garaging location of the vehicle. Only results for counties with at least 1,000 years of collision coverage exposure are shown. Results Map 1 shows average MPD in the United States by county. The Northeast, south Florida, and West Coast predominately had low average MPD. This may be due to more urban areas, greater use of public transportation, or higher percentage of retirees. The highest average MPD was primarily in the Southern states between Texas and South Carolina, in the outer suburbs of metropolitan areas, and in some counties containing federal Indian reservations. Map 1: by county, 2005 14 models HLDI Bulletin Vol 32, No. 28 : December 2015 2

Maps 2 and 3 focus on the high average MPD regions in the Southeastern and Southwestern United States, respectively. In Mississippi, over half of the counties had average MPD of 47 or more. None of the counties had average MPD less than 35. In Louisiana, over one-third of the counties had average MPD of 47 or more, and just two had MPD less than 35 (both in the New Orleans-Metairie metropolitan area). Generally, the counties with lower average MPD were central urban counties of metropolitan areas. In Texas, the central counties for Austin, Dallas, Houston, and San Antonio had average MPD of 35 38. The low average MPD in much of Florida likely results from the high number of retirees and elderly drivers (average MPD is about 50 percent lower for rated drivers age 80 99 compared with ages 20 44, HLDI 2015, Vol.32, No.31). Map 2: by county for southeastern United States, 2005 14 models Shreveport Little Rock Memphis Jackson Chattanooga Huntsville Atlanta Birmingham Montgomery Columbus Charlotte Columbia Baton Rouge New Orleans Mobile Tallahassee Jacksonville Tampa Orlando Miami HLDI Bulletin Vol 32, No. 28 : December 2015 3

Map 3: by county for southwestern United States, 2005 14 models Santa Fe Albuquerque Amarillo Tulsa Oklahoma City Phoenix Lubbock Tucson Dallas El Paso San Antonio Austin Houston Corpus Christi HLDI Bulletin Vol 32, No. 28 : December 2015 4

Map 4 shows average MPD for counties in the New York-Newark-Jersey City metropolitan area. The five boroughs (Bronx, Kings, New York, Queens, and Richmond) had the lowest average MPD of 23 27. Pike County, Pennsylvania, had the highest average MPD of 44. The average MPD tended to increase as the distance from the urban center increased. Map 4: by county for New York-Newark-Jersey City metropolitan area, 2004 2015 models Dutchess Pike Orange Putnam Sussex Passaic Rockland Westchester Bergen Hunterdon Morris Somerset Bronx Essex New York Hudson Queens Union Kings Richmond Nassau Suffolk Middlesex Ocean Monmouth HLDI Bulletin Vol 32, No. 28 : December 2015 5

Map 5 shows average MPD for counties in the Washington-Arlington-Alexandria metropolitan area. The centralmost counties of the District of Columbia, Arlington, Alexandria, and Falls Church had the lowest average MPD of 27 30. Average MPD generally increased as counties were farther from the urban center. Clarke County, Virginia, had the highest average MPD of 46. Map 5: by county for Washington-Arlington-Alexandria metropolitan area, 2005 14 models Clarke Jefferson Loudoun Frederick Montgomery Warren District of Columbia Fauquier Fairfax Prince George's Rappahannock Prince William Charles Calvert Culpeper Stafford Spotsylvania HLDI Bulletin Vol 32, No. 28 : December 2015 6

Map 6 shows average MPD for counties in the Atlanta-Sandy Springs-Roswell metropolitan area. The central county of Fulton had the lowest average MPD of 37, and the far Southeastern county of Jasper had the highest average MPD of 52. Map 6: by county for Atlanta-Sandy Springs-Roswell metropolitan area, 2005 14 models Bartow Pickens Cherokee Dawson Forsyth Haralson Paulding Cobb Gwinnett Barrow Douglas ATLANTA DeKalb Walton Carroll Fulton Clayton Rockdale Newton Morgan Fayette Henry Heard Coweta Spalding Butts Jasper Meriwether Pike Lamar HLDI Bulletin Vol 32, No. 28 : December 2015 7

Tables 1 and 2 list counties with the lowest and highest average MPD, respectively. Counties with the lowest average MPD predominately were islands, isolated areas in Alaska, and in New York City. Nantucket County (Nantucket Island), Massachusetts, had the lowest average MPD of 19. Other island counties with low average MPD were three Hawaiian Islands (Kauai, Maui, and Honolulu); San Juan County, Washington; and Kodiak Island, Alaska. Four counties from the New York City area (Kings, New York, Queens, and Richmond) and San Francisco County (California) also had low average MPD (24 27). Many of the Alaskan counties with low average MPD are not connected to outside areas by roads. The 20 counties with the highest average MPD all had low vehicle densities (fewer than 50 vehicles per square mile). Shannon County, South Dakota, had the highest average MPD of 68. Table 1: Counties with the Lowest Average Miles per Day, 2005 14 Models State County Metropolitan Statistical Area Number of Vehicles per Square Mile Exposure (Insured Vehicle Years) Average Miles per Day Massachusetts Nantucket NA 251 500 25,239 19.1 Alaska Sitka NA 50 3,388 20.7 Alaska Bethel NA 50 1,281 21.5 Alaska Kodiak Island NA 50 10,791 21.6 Alaska Petersburg NA 50 1,190 21.9 Alaska North Slope NA 50 1,099 22.6 Alaska Nome NA 50 1,041 22.7 Alaska Ketchikan Gateway NA 50 7,491 22.9 New York Kings New York-Newark-Jersey City, NY-NJ-PA >1,000 1,107,801 23.8 Washington San Juan NA 101 250 14,526 24.6 Alaska Prince Of Wales-Hyder NA 50 1,656 24.7 Alaska Haines NA 50 1,226 25.0 Alaska Juneau NA 50 19,777 25.2 Hawaii Kauai NA 101 250 56,313 25.4 Hawaii Maui Kahului-Wailuku-Lahaina, HI 101 250 114,502 25.4 New York New York New York-Newark-Jersey City, NY-NJ-PA >1,000 660,879 26.0 New York Queens New York-Newark-Jersey City, NY-NJ-PA >1,000 1,848,858 26.2 Hawaii Honolulu Urban Honolulu, HI >1,000 1,021,652 26.4 New York Richmond New York-Newark-Jersey City, NY-NJ-PA >1,000 966,087 26.7 California San Francisco San Francisco-Oakland-Hayward, CA >1,000 782,602 26.9 U.S. Total 36.2 HLDI Bulletin Vol 32, No. 28 : December 2015 8

Table 2: Counties with the Highest Average Miles per Day, 2005 14 Models State County Metropolitan Statistical Area Number of Vehicles per Square Mile Exposure (Insured Vehicle Years) Average Miles per Day South Dakota Shannon NA 50 4,810 68.0 Arizona Apache NA 50 64,534 62.6 South Dakota Todd NA 50 3,565 59.5 North Dakota Sioux Bismarck, ND 50 2,527 58.7 Louisiana St. Helena Baton Rouge, LA 50 4,853 55.8 Montana Big Horn NA 50 11,007 54.6 Mississippi Tallahatchie NA 50 5,142 54.2 Mississippi Benton Memphis, TN-MS-AR 50 2,261 54.0 Mississippi Holmes NA 50 11,216 53.8 Utah San Juan NA 50 10,590 53.6 Mississippi Greene NA 50 5,520 53.3 Mississippi Sharkey NA 50 1,489 53.3 Georgia Marion Columbus, GA-AL 50 4,708 53.1 Florida Liberty NA 50 5,338 53.0 South Dakota Corson NA 50 2,488 52.8 Alabama Lowndes Montgomery, AL 50 5,898 52.7 New Mexico McKinley NA 50 63,355 52.6 Louisiana West Carroll NA 50 10,155 52.5 Georgia Brantley Brunswick, GA 50 12,698 52.3 Texas Delta NA 50 4,822 52.1 U.S. Total 36.2 Conclusion Average MPD was lowest in the northeast, south Florida, and the west coast. Counties with the highest average MPD were primarily located in the southern states. In metropolitan areas, average MPD was lowest in the central most urban counties and higher in the more suburban counties farther from the urban centers. These results are consistent with the earlier HLDI study. The Highway Loss Data Institute is a nonprofit public service organization that gathers, processes, and publishes insurance data on the human and economic losses associated with owning and operating motor vehicles. DW201512 BT Highway Loss Data Institute 1005 N. Glebe Road, Suite 700 Arlington, VA 22201 +1 703 247 1600 iihs-hldi.org COPYRIGHTED DOCUMENT, DISTRIBUTION RESTRICTED 2015 by the Highway Loss Data Institute. All rights reserved. Distribution of this report is restricted. No part of this publication may be reproduced, or stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the copyright owner. Possession of this publication does not confer the right to print, reprint, publish, copy, sell, file, or use this material in any manner without the written permission of the copyright owner. Permission is hereby granted to companies that are supporters of the Highway Loss Data Institute to reprint, copy, or otherwise use this material for their own business purposes, provided that the copyright notice is clearly visible on the material.