I can understand the frustration of residents dealing with increased scofflaw-ism by motorists on Washington Boulevard due to the reduced traffic throughput on Madison. However, I doubt that lowering speed limits, which further reduces traffic throughput, will solve the problem. Any solution has to address the underlying problem, to wit, insufficient capacity of the roads as currently configured.
My suggestion is to make one of the streets one-way eastbound, the other one-way westbound. This will eliminate traffic stoppages due to left-turners and allow for improved coordination of the traffic lights. For even further improvement, restrict parking to one side of Washington.