Lower Speed Limits and Truck Restrictions on I-10 over Atchafalaya
Thursday, August 28, 2003 at 12:00:00 AM
 Gov. Mike Foster announced today that lower speed limits and lane restrictions for commercial vehicles traveling on I-10 over the Atchafalaya Basin will go into effect as soon as signs can be made and installed.  The changes involve lowering the speed limit for commercial trucks having ten or more wheels from the current 60 miles per hour to 55 and restricting truck travel to the right lane.  These recommendations, approved by Foster, were made by Department of Transportation and Development (DOTD) Secretary Kam Movassaghi and Superintendent of Louisiana State Police Terry Landry.

            “I am extremely concerned for the safety of travelers on the elevated portion of I-10 over the Atchafalaya,” said Foster.  “Slowing the big trucks down and keeping them in the right lane is not only the right thing to do, it will save untold numbers of lives.”

            The changes announced today are based on recommendations submitted to Movassaghi and the governor by an interagency task force that was formed in 1998 following a series of crashes on I-10 over the Atchafalaya Basin.  The task force’s initial report in 1999 included a number of recommendations to improve safety on five elevated interstate segments in south Louisiana:  I-10 over the Atchafalaya Basin, I-10 over the Bonnet Carre Spillway, the I-10 New Orleans East Twin Spans, I-55 over the Manchac Swamp and I-310 over the Labranche Wetlands.  The task force reconvened in June 2003 to review the status of initial recommendations and current crash statistics.  While the review was being conducted, an eleven-vehicle crash occurred on the I-10 over the Atchafalaya Basin, resulting in five fatalities.

            According to Movassaghi, “Based on their analysis of available crash data and new federal research, and considering the heavy truck traffic on the I-10 Atchafalaya Basin and recent fatalities, the task force recommended and I have approved a speed limit of 55 mph for trucks and a restriction of truck traffic to the right lane on this segment of interstate.”    These changes will be implemented on a pilot basis, after which DOTD will determine the effectiveness of these measures and make a decision on implementing the restrictions on other interstate segments. 

            Movassaghi added that a Transportation Research Board national study recently reported that 31 percent of state highway agencies have implemented differential speed limits for passenger cars and trucks and another 9 percent were considering differential speed limits.  States with uniform speed limits experienced higher truck-into-car collisions, and although there was no difference in fatality rates, states with uniform speed limits did experience a higher proportion of accidents with injuries. 

As to truck lane restrictions, a recent test in Houston for an eight-month period on one freeway indicated a 68 percent reduction in accidents. 

            “We want to do everything possible to improve safety on these elevated segments and are certainly willing to try anything that might help,” Movassaghi said.  Other recommendations included in the initial task force study that have been or are being implemented include installation of an automatic weather detection and warning system on three I-10 elevated sections, installation of additional bridge rail reflectors on all elevated sections and changeable speed limit advisory signs to reduce posted speed limit during inclement weather.  Safe driving public relations campaigns have also been conducted.

            Another task force recommendation, electronic enforcement of speed limits on elevated sections of the interstate, was proposed during the 1999 legislative session but failed to pass.  DOTD is also pursuing the group’s recommendation to provide additional Motorist Assistance Patrols on designated interstate sections.

            Interagency task force members represented Louisiana State Police, the Louisiana Highway Safety Commission, the Federal Highway Administration and Louisiana Motor Transport Association (LMTA), a state commercial trucking association, which did not support truck restrictions. 

            Movassaghi echoed the task force’s conclusion by stating, “The state can do its part by implementing measures recommended in this study, but nothing we do will have as great an effect on highway safety as motorists driving in a reasonable and prudent manner.”