I've travelled through areas where the number of signs causes real information-overload.
Many are highly reflective, reducing visibility at night. Most street-lights I've see could use much better covers/reflectors too, to reduce the amount of light going directly into the drivers eyes.
More than all that though, if you pull most of the signs people will have to think about what they are doing. Scary when you're not used to it, but it makes sense that drivers who are thinking about what they are doing will do it better.
Start holding people accountable for their actions & pretty soon everyone will be paying attention to how they drive. Another good step toward achieving that would be to stop calling crashes 'accidents'. There are true accidents out there, but most crashes are the result of inattention or plain bad driving.