To improve the safety of the riders, spectators and the race convoy, the UCI Management Committee decided to limit the peloton size to a maximum of 176 riders in all events on the UCI International Road Calendar. Therefore, a maximum of 7 riders will now be allowed per team in all men’s road races (except Grand Tours, 8). In the UCI Women’s WorldTour, there will be a maximum of 6 riders per team in one-day races, 7 in stage-races.
http://www.uci.ch/pressreleases/the-uci-announces-extensive-modernisation-regulations/
My two cents: this measure will NOT improve the safety of anyone involved, but in the long term will cost some riders their job as overall team sizes will likely shrink.