Mandated by an act passed earlier this year by state lawmakers, the Arkansas Department of Transportation has recently released a speed limit review and made it available for public comment. The review examines the feasibility of increasing speed limits on state highways.
Earlier this year, the Arkansas State Legislature passed Act 1097, which allows the state to increase highway speeds to 75 mph after conducting an engineering and traffic investigation. On Oct. 30, ArDOT released the draft study for a 45-day public comment period.
ArDOT’s study recommends a 75-mph speed limit for rural interstates and 65 mph for urban interstates. Unless an engineering study determines the need for a lower speed limit, the study also recommends 65 mph on rural multilane highways. A speed limit of 55 mph is suggested for other rural highways, with a possible increase to 60 mph on individual highways pending an engineering study justifying the increase.
Currently, speed limits are set at 70 mph for rural freeways, 60 mph for urban freeways, 55-65 mph for rural multilane highways and 55 mph for all other rural highways. If accepted, speed limits will either stay the same or increase by 5 mph.
According to the Insurance Institute for Highway Safety, 12 states (including Arkansas) allow maximum speed limits of 75 mph on rural interstates by law. A six state cluster – Idaho, Montana, Nevada, South Dakota, Utah and Wyoming – allow speeds up to 80 mph. Texas is the only state allowing up to 85 mph. Most states have a maximum speed of 70 mph, with several states in the Northeast lowering the limit to 65 mph. Hawaii has the lowest maximum speed limit at 60 mph.
After the 1974 Emergency Highway Energy Conservation Act – which set maximum speed limits on all highways at 55 mph – was repealed in 1995, Arkansas established maximum speeds at 70 mph. Heavy trucks were restricted to 65 mph. However, the truck speed differential was eliminated fairly recently in 2015.
ArDOT’s draft review found that after the speed limit increase in 1996, fatality rates increased by 9.4 percent. The review also states “that an upward trend in the fatal crashes in 2015 continued when the truck-specific speed limit of 65 mph was removed.” As noted, fatalities were already trending upward. Furthermore, fuel prices had decreased dramatically in 2015, increasing the amount of travel across all motorist types.
The review points out that the state’s fatality rate peaked for all interstates in 2000, four years after the speed limit was increased. For rural interstates, the fatal crash rate peaked in 2005 while the fatality rate peaked in 1998, two years after the increase. Although the numbers suggest a positive correlation between speed limit changes and fatality rates, the data does not prove any causation.
Conversely, ArDOT’s numbers reveal a declining trend for fatal and serious injury crash rates since the peak in 2000. This is despite a consistent increase in vehicle miles traveled. ArDOT suggests technology may contribute to the decline with so many additional safety features available in vehicles. The review goes on to cite numerous other studies that show speed limit increases result in higher fatal crash rates.
According to the review, the 85th percentile speed in Arkansas in 2016 was 71 mph on rural freeways, 59 mph on urban freeways and 67 mph on rural multi-lane highways. The 85th percentile speed is the speed at or below which 85 percent of motorists are driving, and the Manual on Uniform Traffic Control Devices states that the posted speed limit should be within 5 mph of the 85th percentile speed.
To view the full review and leave comments, click here.
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