( CNN ) -- The driver of a train that jumped the tracks last month at Chicago 's O'Hare International Airport -- after having reportedly `` dozed off '' -- has been fired , a transit authority spokeswoman said Friday . The early morning incident at one of the nation 's busiest airports was the operator 's second serious safety violation , according to Chicago Transit Authority spokeswoman Tammy Chase . That said , Chase said the woman was primarily terminated because of the severity of that crash , which injured 32 people . The development came the same day the transit authority announced several policy changes aimed at enhancing safety . They include requirements that train operators not be working at least one day in a seven-day period and must have at least 10 hours off between shifts ( up from the previous 8-hour mandate ) . Train operators also ca n't work more than 12 hours ( including layover times and non-driving duties ) in a 14-hour period . Fresh restrictions were also placed on those in their first year of operating trains : They ca n't do so more than 32 hours a week , though these employees can `` work other rail-related duties besides operating trains in their other work hours , '' the transit authority said in its statement Friday . These revised guidelines are `` nearly identical '' to those used by other transit agencies , according to Chase . She said `` nothing about the operator 's work schedule suggests that fatigue should have played a factor in her performance . '' The driver had a day off four days before the incident , had n't worked for 18 hours before coming to work that day and worked 55.7 hours in the seven previous days ( less than 44 of those as a rail operator ) , according to the transit authority spokeswoman . That said , Chase acknowledged , `` The O'Hare incident prompted us to take a closer look at our scheduling . '' The wreck occurred at 2:52 a.m. on March 24 , when an eight-car train failed to stop at the end of the Blue Line when it arrived at the airport station , a Chicago fire official said . The lead car appeared to have climbed an escalator adjacent to the passenger platform . `` I 've investigated many accidents and trains do different things , '' National Transportation Safety Board investigator Tim DePaepe said of the train climbing the escalator . `` It 's all about kinetic force . I have not seen an accident like this , personally . '' A union official told reporters last month that the train 's driver may have fallen asleep , CNN affiliate WLS reported . `` There are indications that she dozed off , yes , '' Amalgamated Transit Union Local 308 President Robert Kelly said , according to WLS . CNN 's Alan Duke and Jennifer Feldman contributed to this report .
NEW : Official : No reason , based on schedule , that fatigue should have been a factor . NEW : Incident did prompt transit agency to look at train operator scheduling . 32 people were injured in last month 's incident at the end of Chicago 's Blue Line . A union official had said there were `` indications '' that the train operator `` dozed off ''