monika makes a valid point - any traffic calming measures must not slow the ambulances down.
So I withdraw my suggestion to put humps on this road.

I now suggest we make Manor mnt 2-way, but put a barrier up between Davids Rd and Manor Mnt - (but give the ambulance station dual access into both roads.)
Likewise with pearcefield Ave. Both barriers could be open outside of the rush hour. Residents of Davids Rd to be issued with a fob.

Not sure the cost of this, but car parks used to all have barriers - this is just an extension of that idea. If our technology is no longer up to this, then the gates will have to be manually opened and closed at the said times.
He/she could also be in charge of the Perry Vale station side entrance - we could call this person the master of the keys.