If the speed displays are not working, then, I would say, it is time for the Ottawa Police to write more tickets, using both photo radar and traffic cops.

If the average speed is 10 km/hr over the speed limit, start issuing tickets at 15 km/hr over. Then move down slowly. With enough tickets in a year, the average speeds will come down.

And someone other than me is paying more taxes. Works good for me.

I spent a month in Egypt. No speed limits there. Made Montreal roads seem tame. Lots and lots of wrecked cars on the sides of the road.