The last time I used lockers at G du N, you had to go through security (like the airports) to get into the locker area. Due to the hassle this entails, locker availability is not (now) a problem. [PS: Before they instituted this security system (15 years ago(?)), the lockers required exact change, and virtually every merchant had a sign "pas de change", indicating they would not make change, and the money changers always had long lines--now the agents at locker security will make change.^]