The Louisiana Department of Transportation and Development is raising the speed limit on rural portions of I-49 in Avoyelles, Natchitoches and Rapides parishes from 70 mph to 75 mph. The new speed limit will go into effect in the next two weeks, as speed signs are posted.
Last year the Legislature passed a law allowing DOTD to set higher speed limits if traffic studies prove the higher speeds are safe and reasonable. DOTD engineers routinely study speed limits on state maintained roadways to ensure they are set correctly, and its traffic engineering office in Alexandria recently launched a traffic study to help determine what the safest and most efficient posted speed limit should be on rural portions of I-49. The study determined that 85 percent of all drivers traveling on this section of I-49 are traveling at or below 75 mph.
National studies and practices have shown that setting the speed limit at the 85th percentile can help to reduce crashes along the roadway. Speed limits set higher than the 85th percentile are considered unreasonable, and speed limits set below the 85th percentile do not move traffic efficiently. In addition, speed limits set below the 85th percentile cannot be enforced effectively and are not voluntarily observed by motorists, according to DOTD.
The new speed limit includes the entire sections of I-49 in Avoyelles and Natchitoches parishes. In Rapides Parish, the new speed limit will be in effect from the Natchitoches Parish line to three miles north of U.S. 71, and from one mile south of U.S. 71 to the Evangeline Parish line. DOTD says highway features on these sections of rural roadway can safely accommodate higher speeds.
To ensure the safety of motorists, DOTD personnel will install automated speed and count stations along the roadway to monitor speeds and crashes along this section of I-49. DOTD will reexamine the speed limit increase if at any time data supports a new study.
Louisiana is not alone in its speed limit increases. Texas, for example, which already has some of the country’s highest speed limits, passed a House bill last week allowing a speed limit of 85 mph on some highways. The Texas Senate is considering a similar bill.