Since the early 2000s, a real attention is paid to physical impairments arising in large-scale optical networks. One cost-effective solution to cope with transmission impairments is to deploy 3R (re-amplifying, re-shaping, and re-timing) regenerators in a limited number of network nodes (i.e., translucent networks). Taking into account the simultaneous effect of four transmission impairments (amplified spontaneous emission, chromatic dispersion, polarization mode dispersion, and nonlinear phase shift), we propose a novel exact approach for impairment-aware network planning. In contrast with previous works, we investigate the problem under pre-planed dynamic traffic. Our proposal takes advantage of the dynamics of the traffic pattern so that regeneration resources may be shared among non-concurrent requests. Given a network topology and a set of pre-planned requests, we target the minimum number of regenerators or/and regeneration sites. Obtained results emphasize the mutual impact between requests' time-correlation and regenerator concentration.