After having proposed methods to compute secure paths dedicated to bicycle in order to improve safety for bike users [1], we are interested here in the improvement of the cycle network in order to increase the overall safety of the users. While the development of mobility with low GHG emissions is an important issue for all cities, it now appears necessary to intelligently deploy bicycle facilities to strengthen users' feelings of safety [2, 3, 4]. The problem we are addressing here consists in using a set of GPS tracks corresponding to paths taken by cyclists, to propose improvements to the cycle network on the basis of this set of paths, eg. installation of cycle lanes on one or more sections, in order to increase the overall safety of users.