The first part of a study by the Arizona Department of Transportation on reducing an often-congested section of Interstate 17 is finished. Officials say the idea of restricting trucks to the right is working on I-17 between Black Canyon City and the Sunset Point rest area.
Last December, Arizona DOT crews erected signs telling truckdrivers of the temporary right-lane requirement. The regulation only affects vehicles weighing more than 26,000 pounds, including cargo.
The restriction was established to avert the climbing accident rate on certain state highways. Reportedly, north of the Phoenix area, the average annual accident rate during the past five years on I-17 was 18.6 crashes per mile. Between Black Canyon City and the rest area, there were 30.3 incidents per mile.
Officials will look at accident data and other factors on I-17 before ordering the requirement on other highways. That process is expected to take a year or more.
Transportation officials say the right-lane-only requirement will never be put into play on Phoenix-area freeways because convoys will interfere with cars at entrance and exit ramps.