This paper presents an integrated approach for trajectory generation and time coordination for multiple vehicles, combined with collision avoidance. Pythagorean Hodograph B'ezier curves are used to generate desired feasible trajectories that satisfy the dynamic constraints of the vehicles, and guarantee spatial separation between the paths for safe operation. Time coordination ensures that the temporal requirements of the mission are met. Collision avoidance with dynamic obstacles is achieved by properly adjusting the speed profiles of the vehicles along the corresponding paths. A simulation scenario is presented where three quadrotors are coordinating their positions along pre-computed paths, while at the same time avoiding moving objects. The results show that the integrated approach achieves time coordination along feasible paths, and that the collision avoidance algorithm allows for safe operation in the presence of moving obstacles.