A new study from the AAA Foundation for Traffic Safety took a look at 12 roadway sites and found that "raising posted speed limits may do little to save time and increase traffic flow but could lead to more crashes, injuries, and deaths."
Out of the 12, six sites raised the posted speed limit and six lowered it. The top key findings from the study include: Two out of the three Interstate Highways having increased crashes when speed limits were raised, lowered speed limits at two principal arteries experiencing a decrease in crashes and overall small changes in travel times for both raised and lowered circumstances.
“Our study analyzed before-and-after data on a dozen roadways that raised or lowered posted speed limits and found no one-size-fits-all answer regarding the impact of these changes,” said Dr. David Yang, president and executive director of the AAA Foundation. “However, it is critical to consider the safety implications when local transportation authorities contemplate making changes with posted speed limits.”