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Model Traffic Ordinance

This page provides a basic overview of the Washington Model Traffic Ordinance (MTO), including legal citations.


The Washington Model Traffic Ordinance (MTO) is a uniform compilation of traffic laws which may be adopted by reference by a Washington city, town, or county to serve as the local traffic ordinance. Local jurisdictions may also exclude any section(s) from the MTO that they do not wish to include in the local traffic ordinance or add additional sections if desired to supplement the MTO.

The Model Traffic Ordinance is contained in Ch. 308-330 WAC. The Department of Licensing, in consultation with the Washington State Patrol and the Traffic Safety Commission, must periodically update the MTO.

The Washington MTO was developed in response to the pressing need of many cities, towns, and counties to have an economical and effective way of keeping their traffic ordinances up-to-date. Local jurisdictions do not have to adopt individual state traffic laws every time the state laws are amended if they have adopted the MTO by reference.

The MTO was first enacted by the state legislature in 1975 and codified in Ch. 46.90 RCW. In 1993, the legislature changed the MTO from a statutory process to an administrative rule-making process in order to allow more timely updates that did not require legislative action. (However, some RCW sections are adopted by reference in the WAC sections, so some sections can effectively be modified by the state legislature.)

Washington's MTO was based on the Model Traffic Ordinance of the National Committee on Uniform Traffic Laws and Ordinance. In 1972 the Washington Traffic Safety Commission contracted with MRSC for a federally funded project to compare the Uniform Code with the state's motor vehicle laws and prepare a model traffic ordinance that could be adopted by reference by cities, towns, and counties.

Legal References

  • Ch. 308-330 WAC – Washington Model Traffic Ordinance administrative rules
  • Ch. 46.90 RCW – Authority for Department of Licensing to adopt administrative rules

Adopting or Modifying the Model Traffic Ordinance

Any city, town, or county may adopt the entirety of the Model Traffic Ordinance, or individual sections, by reference. Local jurisdictions may also add additional sections if desired to supplement the MTO.

When adopting the MTO, it is extremely important to follow the exact statutory procedures included in state statute, as failure to do so may invalidate the provisions. The statutory procedures can be found below:

Any amendment to the Model Traffic Ordinance automatically amends any city, town, or county ordinance that has adopted the MTO, or the amended portion of the MTO, by reference (WAC 308-330-010 and RCW 46.90.010). It is not necessary for the local legislative body to take any action for these amendments to be effective locally.

However, if a jurisdiction has written additional provisions to its traffic ordinances, they should be reviewed for conflicts with any newly enacted MTO provisions.

Court Decisions

City clerk's failure to authenticate, record, and file appropriate copies of the MTO invalidated the ordinance.

Bothell v. Gutschmidt, 78 Wn. App. 654 (1995) – Appellants challenged the validity of a city's ordinance that adopted portions of the Washington Model Traffic Ordinance (MTO) by reference. The District Court ordered dismissal of the DWI charges against the appellants ruling that the city clerk's failure to authenticate, record, and file appropriate copies of the MTO invalidated the ordinance

Last Modified: April 02, 2021