Breaking with the trend of giving the elite women the first start, Boston Marathon officials cite safety concerns.

Ladies first? Not at the 2020 Boston Marathon, race officials announced on Thursday.

For the first time since 2004, the elite women’s field will start the race in Hopkinton, Massachusetts behind the elite men. The men’s elite field will start at 9:37 a.m. and the women will take off at 9:45 a.m. on April 20. The first wave of non-elite competitors will take off at 10 a.m.

Race officials said the old, narrow New England streets were creating safety hazards when the front of the elite men’s field caught the back of the women’s field. The leaders of each race are accompanied by vehicles, including a press truck, motorcycles, and bikes, and the roads from Hopkinton to Copley Square don’t allow enough room to squeeze everybody through with ease.

Also this year the Boston race will feature a Para Athletics Division—elite athletes with visual, upper-limb, and lower-limb impairments are competing for prize money and the race will serve as the trials for the 2020 U.S. Paralympic team. This division will start the race at 9:50 a.m., ten minutes before wave one.

The elite women were originally granted the first start 16 years ago to enhance the television exposure and allow them to compete unimpeded by other runners, better able to see and respond to the tactics of those they are racing. It was a move initiated by the New York City Marathon that quickly caught on at other races. The spotlight is critical for the earning potential of female athletes, whether in the form of sponsorships or subsequent appearance fees—an opportunity most marathoners get once or twice each year.

“Keeping participant safety and their experience at the forefront of all decision making, we have taken a data-driven and analytical approach to determine the most optimal start times for all divisions,” said Tom Grilk, Chief Executive Officer of the Boston Athletic Association, in a written statement.

Boston officials say the chance that the lead vehicles will have to pass anybody will be reduced and the television broadcast in 2020 will increase the airtime of the later miles in the women’s race. The outcome of the men’s race will already be decided.

“The [Boston Athletic Association] has taken industry-leading steps to ensure our safety and a world-class experience,” said Desiree Linden, the 2018 Boston champion, in a written statement. “I am especially excited about the additional coverage in the final miles—all the world’s eyes will be on us as we head for the finish in Boston.”

Members of the men’s and women’s elite fields are invited by sponsor John Hancock. Additional invitations to the advanced elite starts are offered based on qualifying times, typically mirroring the Olympic Trials qualifying standard of 2:45 for women and 2:19 for men.

Linden is racing Boston again this year after she competes at the U.S. Olympic Trials on February 29. She will face a strong international field in Boston, including defending champion Worknesh Degefa of Ethiopia.