MO HB1804

Requires courts to mandate ignition interlock devices for persons convicted of first intoxication-related traffic offenses and mandates devices for second or subsequent offenses, with installation required for at least six months from driver's license reinstatement.

Expands ignition interlock requirements to persons suspended or revoked for violations under subdivisions (8) or (9) of section 302.302, requiring proof of device installation as a condition of license reinstatement and maintenance for at least six months.

Requires ignition interlock devices for persons with prior alcohol-related enforcement contacts seeking restricted driving privileges following license suspension or revocation, with devices required during the restricted driving period.

Prohibits renting, leasing, or lending motor vehicles to persons with restricted driving privileges unless the vehicle is equipped with a functioning, certified ignition interlock device; violators face class A misdemeanor penalties.

Makes failure to maintain ignition interlock device proof with the director a class A misdemeanor offense, triggering license resuspension or revocation.