Home The 100 busiest county routes In 2022–23 the IRS listed 53,614 routes between two counties, carrying 6,482,290 returns. The busiest 100 of them account for 12% of that traffic, and they are short: half run 30 miles or less. The longest is also the only one that crosses a state line: Los Angeles County, CA to Clark County, NV, 230 miles.
Returns moving along each route, with the count in the opposite direction, 2022–23 Route Returns Coming back Miles Los Angeles County, CA Orange County, CA 19,802 16,006 45 Los Angeles County, CA San Bernardino County, CA 18,325 10,887 127 Miami-Dade County, FL Broward County, FL 17,471 10,482 40 Orange County, CA Los Angeles County, CA 16,006 19,802 45 Harris County, TX Fort Bend County, TX 14,433 11,572 32 New York County, NY Kings County, NY 14,123 7,421 10 Dallas County, TX Tarrant County, TX 14,066 11,085 30 Dallas County, TX Collin County, TX 12,881 9,550 32 Harris County, TX Montgomery County, TX 12,733 7,410 31 Travis County, TX Williamson County, TX 12,394 8,377 29 Kings County, NY Queens County, NY 12,183 8,138 6 Fort Bend County, TX Harris County, TX 11,572 14,433 32 Los Angeles County, CA Riverside County, CA 11,161 6,767 133 Cook County, IL DuPage County, IL 11,143 8,374 23 San Bernardino County, CA Riverside County, CA 11,141 9,520 79 Tarrant County, TX Dallas County, TX 11,085 14,066 30 San Bernardino County, CA Los Angeles County, CA 10,887 18,325 127 Maricopa County, AZ Pinal County, AZ 10,805 6,549 72 King County, WA Snohomish County, WA 10,534 7,334 39 Broward County, FL Miami-Dade County, FL 10,482 17,471 40 Queens County, NY Nassau County, NY 10,413 4,717 14 Dallas County, TX Denton County, TX 9,837 6,817 36 Suffolk County, MA Middlesex County, MA 9,674 7,512 22 Collin County, TX Dallas County, TX 9,550 12,881 32 Riverside County, CA San Bernardino County, CA 9,520 11,141 79 King County, WA Pierce County, WA 9,291 6,086 34 Denver County, CO Arapahoe County, CO 8,748 7,829 30 Wayne County, MI Oakland County, MI 8,467 7,246 27 Williamson County, TX Travis County, TX 8,377 12,394 29 DuPage County, IL Cook County, IL 8,374 11,143 23 Orange County, CA Riverside County, CA 8,367 5,376 102 Hillsborough County, FL Pasco County, FL 8,182 4,065 30 Queens County, NY Kings County, NY 8,138 12,183 6 Collin County, TX Denton County, TX 8,067 7,417 31 Fulton County, GA DeKalb County, GA 7,989 7,888 14 DeKalb County, GA Fulton County, GA 7,888 7,989 14 Baltimore City, MD Baltimore County, MD 7,832 6,454 10 Arapahoe County, CO Denver County, CO 7,829 8,748 30 Orange County, FL Seminole County, FL 7,701 6,288 17 Middlesex County, MA Suffolk County, MA 7,512 9,674 22 Broward County, FL Palm Beach County, FL 7,488 5,681 32 Kings County, NY New York County, NY 7,421 14,123 10 Denton County, TX Collin County, TX 7,417 8,067 31 Montgomery County, TX Harris County, TX 7,410 12,733 31 Snohomish County, WA King County, WA 7,334 10,534 39 Orange County, FL Osceola County, FL 7,271 5,567 33 Denver County, CO Jefferson County, CO 7,255 5,051 23 Oakland County, MI Wayne County, MI 7,246 8,467 27 Alameda County, CA Contra Costa County, CA 7,141 4,871 19 Cook County, IL Will County, IL 6,972 4,824 35 Nassau County, NY Suffolk County, NY 6,970 4,060 49 New York County, NY Queens County, NY 6,844 4,241 11 Denton County, TX Dallas County, TX 6,817 9,837 36 Riverside County, CA Los Angeles County, CA 6,767 11,161 133 St. Louis City, MO St. Louis County, MO 6,585 5,157 11 Santa Clara County, CA Alameda County, CA 6,578 4,634 32 San Diego County, CA Riverside County, CA 6,563 5,038 66 Pinal County, AZ Maricopa County, AZ 6,549 10,805 72 Baltimore County, MD Baltimore City, MD 6,454 7,832 10 Los Angeles County, CA San Diego County, CA 6,449 4,999 118 Cook County, IL Lake County, IL 6,447 4,959 22 Seminole County, FL Orange County, FL 6,288 7,701 17 Los Angeles County, CA Ventura County, CA 6,216 4,200 51 Pierce County, WA King County, WA 6,086 9,291 34 Hennepin County, MN Ramsey County, MN 6,020 5,844 18 Los Angeles County, CA Clark County, NV 5,979 3,176 230 Suffolk County, MA Norfolk County, MA 5,965 4,217 14 Philadelphia County, PA Montgomery County, PA 5,924 3,939 19 Ramsey County, MN Hennepin County, MN 5,844 6,020 18 New York County, NY Bronx County, NY 5,817 4,691 8 Salt Lake County, UT Utah County, UT 5,735 4,666 40 Palm Beach County, FL Broward County, FL 5,681 7,488 32 Tarrant County, TX Denton County, TX 5,613 4,908 32 Osceola County, FL Orange County, FL 5,567 7,271 33 Fulton County, GA Cobb County, GA 5,477 4,775 12 Wayne County, MI Macomb County, MI 5,442 4,183 32 Riverside County, CA Orange County, CA 5,376 8,367 102 Oakland County, MI Macomb County, MI 5,180 5,056 24 DeKalb County, GA Gwinnett County, GA 5,163 4,227 17 St. Louis County, MO St. Louis City, MO 5,157 6,585 11 Harris County, TX Brazoria County, TX 5,157 3,625 48 Bronx County, NY Westchester County, NY 5,118 2,232 22 Denver County, CO Adams County, CO 5,110 3,626 30 Travis County, TX Hays County, TX 5,064 2,606 24 Macomb County, MI Oakland County, MI 5,056 5,180 24 Jefferson County, CO Denver County, CO 5,051 7,255 23 Riverside County, CA San Diego County, CA 5,038 6,563 66 Hillsborough County, FL Pinellas County, FL 5,025 4,886 26 San Diego County, CA Los Angeles County, CA 4,999 6,449 118 Lake County, IL Cook County, IL 4,959 6,447 22 Denton County, TX Tarrant County, TX 4,908 5,613 32 Pinellas County, FL Hillsborough County, FL 4,886 5,025 26 Contra Costa County, CA Alameda County, CA 4,871 7,141 19 Middlesex County, MA Essex County, MA 4,847 4,184 29 Multnomah County, OR Clackamas County, OR 4,847 3,825 29 Sacramento County, CA Placer County, CA 4,846 3,270 54 Will County, IL Cook County, IL 4,824 6,972 35 Cobb County, GA Fulton County, GA 4,775 5,477 12 Nassau County, NY Queens County, NY 4,717 10,413 14 Bronx County, NY New York County, NY 4,691 5,817 8
Any pair can be checked in the two-county comparison , with four filing years for both directions. The note on routes that run mostly one way ranks them by imbalance.
Short hops across a state line Of the routes crossing a state line, 1,344 run 40 miles or less between county centers. These are the busiest 20.
Interstate routes of 40 miles or less, 2022–23 Route Returns Coming back Miles Cook County, IL 4,226 2,665 32 District of Columbia Prince George’s County, MD 4,089 3,479 10 New York County, NY Hudson County, NJ 3,860 1,667 6 Johnson County, KS Jackson County, MO 3,513 3,355 27 Prince George’s County, MD District of Columbia 3,479 4,089 10 Jackson County, MO Johnson County, KS 3,355 3,513 27 District of Columbia Montgomery County, MD 3,120 2,420 19 Multnomah County, OR Clark County, WA 2,886 1,939 16 Lake County, IN Cook County, IL 2,665 4,226 32 Shelby County, TN 2,544 1,915 22 Montgomery County, MD District of Columbia 2,420 3,120 19 Mecklenburg County, NC York County, SC 2,240 1,389 27 Middlesex County, MA Hillsborough County, NH 2,099 1,149 34 Kings County, NY Hudson County, NJ 2,014 1,142 9 Westchester County, NY Western Connecticut Planning Region, CT 2,005 917 18 District of Columbia Arlington County, VA 2,000 1,789 5 Philadelphia County, PA Camden County, NJ 1,980 1,119 17 Clark County, WA Multnomah County, OR 1,939 2,886 16 DeSoto County, MS Shelby County, TN 1,915 2,544 22 New York County, NY Bergen County, NJ 1,804 1,635 14
The longest busy routes The longest routes carrying at least 300 returns. Of these 20, 12 start or end in Honolulu County, Hawaii.
Longest routes with 300 returns or more, 2022–23 Route Returns Coming back Miles Honolulu County, HI Bexar County, TX 326 257 3,725 Honolulu County, HI El Paso County, CO 328 213 3,371 Maricopa County, AZ Honolulu County, HI 310 377 2,896 Honolulu County, HI Maricopa County, AZ 377 310 2,896 Honolulu County, HI Clark County, NV 1,243 523 2,779 Clark County, NV Honolulu County, HI 523 1,243 2,779 Suffolk County, MA San Francisco County, CA 300 183 2,727 Middlesex County, MA San Francisco County, CA 372 211 2,706 Honolulu County, HI King County, WA 583 335 2,701 King County, WA Honolulu County, HI 335 583 2,701 Honolulu County, HI Pierce County, WA 345 293 2,674 Middlesex County, MA Santa Clara County, CA 455 279 2,653 San Diego County, CA Honolulu County, HI 789 879 2,648 Honolulu County, HI San Diego County, CA 879 789 2,648 San Francisco County, CA Kings County, NY 885 333 2,602 Kings County, NY San Francisco County, CA 333 885 2,602 San Francisco County, CA New York County, NY 1,653 804 2,599 New York County, NY San Francisco County, CA 804 1,653 2,599 Orange County, CA Honolulu County, HI 327 288 2,597 Los Angeles County, CA Suffolk County, MA 430 540 2,589
Source: IRS Statistics of Income, SOI Tax Stats – Migration Data (county-to-county files, 2019–20 to 2022–23; latest release used: 2022–23), retrieved October 28, 2026. County locations: US Census Bureau, 2023 Gazetteer Files. Both are US government works in the public domain; calculations by countymoves, explained in How to read the data .