For a local authority to adjust a maximum speed limit, the local authority must determine on the basis of an engineering and traffic investigation that the maximum speed permitted under existing law is greater or less than is reasonable and safe under the conditions found to exist upon a highway.  Cities and towns may establish a 20-mph speed limit, without first conducting an engineering and traffic investigation, on a nonarterial highway that is within a residence district or business district. 

Every driver of a vehicle must exercise due care to avoid colliding with any pedestrian upon any roadway.  A similar duty of care to avoid colliding with vehicular traffic does not exist for pedestrians walking or otherwise moving on a roadway.

The Secretary of Transportation and local authorities, in their respective jurisdictions, may establish a 20-mph speed limit on nonarterial highways without first conducting an engineering and traffic investigation, regardless of whether the highway is in a residence district or business district.

Pedestrians, when walking on a roadway, are required to exercise due care to avoid colliding with any vehicle on the roadway.