Yes, an obvious and valid flaw, I don't know why you are being down voted. A car with a roof-rack word would prevent the bus passing, assuming the driver sees it. Not to mention cyclists.
And easily fixed. Put multiple warning signs, then hang some chains set at this height limit on roads leading in as a warning (nice loud crash but limited damage), followed by a nice solid bar blocking the section of the road this operates.
Some people ignore these. Or rent a truck and take their usual route.
It's almost that time of year in Boston when many people move c. Sep 1. Some get "Storrowed":