According to Ynet, extremists tried to put up signage that directed men to the newly installed elevators in Modiin mall and women to the older (but larger) elevators. Others tried to tear the signs down. Despite this the extremists claim that the seggregation was being carried out with the agreement of local residents. Clearly not all!
The underlying halachic issue is “yichud” – the rule that an unrelated man and women shouldn’t be in a room together with the door closed. However, this does not necessitate separate elevators.
For one, a mixed group (2 men, 2 women) does not violate yichud since four people in a room doesn’t count as “alone”. Furthermore, Haredi men can do what women, religious and secular, have been doing for decades when the feel uncomfortable getting on an elevator alone with a group of strange men: wait for the next elevator or take the stairs.