The Senate Appropriations Committee recently voted 21-9, in favor of suspending some of the hour of service rule changes that were put in place back in July 2013. The reason? They’re not sure if the rules put in place to increase safety actually work.

The bill will now be voted upon by senate, and should it pass, drivers will no longer be limited to one 34 hour restart in a 168 hour period and the restart will no longer have to include two consecutive 1 a.m. to 5 a.m. periods.

If it passes, these two rules will be suspended for all drivers for a year as the FMCSA performs studies to determine their effectiveness. The studies will be performed on two controlled groups, one following the rules put in place last July and one group that is not.

The American Trucking Association (ATA) President and CEO, Bill Graves, chimed in and said:

“Since these rules were proposed in 2010, ATA has maintained that they were unsupported by science and since they were implemented in 2013 the industry and economy have experienced substantial negative effects as a result. Today, thanks to Senator Collins’ leadership, we are a step closer to reversing these damaging, unjustified regulations. The agency cannot simply regulate based upon guesses.”

All Republicans on the committee voted in favor of reverting these rules, as did 7 democrats.

The amendments were not met without opposition however. Senator Dianne Feinstein, a democrat in California, says trucks “just zoom out all over the highway” in Los Angeles and Long Beach. She claims that the 2013 rule changes have been effective in making sure drivers are rested.

Keep in mind, the 2013 HOS rules are still in effect, as these revisions will now have to be passed by Senate.