Generally revise county speed limits

SB 428 revises how local authorities and county commissions can set speed limits on roads. It allows local authorities to adjust speed limits in various areas, such as urban districts, outside urban districts, and school zones, typically requiring an engineering and traffic investigation. A key change is that boards of county commissioners can now set certain decreased speed limits on county roads, including in school zones, without first conducting an engineering and traffic investigation. The bill also specifies signage requirements for altered limits and mandates consultation with relevant bodies for school zones.