Staying In Your Lane
Mo. Rev. Stat. § 304.015 — the right half, the right-hand lane, and as nearly as practicable entirely within a single lane
The right half. Upon all public roads or highways of sufficient width, a vehicle is driven upon the right half of the roadway, except when overtaking and passing, when placed for and lawfully making a left turn, when the right half is closed to traffic for construction or repair, and on a one-way street.
Within a single lane. Whenever a roadway has been divided into three or more clearly marked lanes, a vehicle is driven as nearly as practicable entirely within a single lane, and is not moved from that lane until the driver has first ascertained that the movement can be made with safety.
The center of three. On a roadway divided into three lanes, the center lane is not used except to overtake and pass where the roadway ahead is clearly visible and the center lane is clear within a safe distance, to prepare for a left turn, or where the center lane is allocated to the driver's direction and sign-posted.
The right-hand lane. On a highway with two or more lanes of traffic proceeding in the same direction, vehicles in motion are driven in the right-hand lane except when overtaking and passing, when preparing to make a proper left turn, or when directed otherwise by markings, signs or signals. A vehicle going less than the normal speed of traffic keeps to the right-hand lane, or as close as practicable to the right-hand edge or curb.
Divided highways. Where a highway is divided into two or more roadways by a physical barrier, a dividing section, or curbs, lines or other markings, driving is to the right of the divider, and a left turn or U-turn on it is made only at an intersection, an interchange, or a signed location.
Heavy trucks. Trucks registered for a gross weight of more than forty-eight thousand pounds are not driven in the far left-hand lane of interstate highways, freeways or expressways within urbanized areas having three or more lanes in the same direction, except to follow traffic control devices or when the right half of the roadway is closed for work.
| What happened | The level |
|---|---|
| What happenedThe violation itself | The levelClass C misdemeanor |
| What happenedA violation that causes an immediate threat of an accident | The levelClass B misdemeanor |
| What happenedA violation from which an accident results | The levelClass A misdemeanor |
City and county ordinances are not on this page. Whether a particular stop, charge or case was handled lawfully is a question for the court that hears it, or a licensed Missouri attorney.
Sources for this section (1)
- Mo. Rev. Stat. § 304.015 — Drive on right of highway — traffic lanes — signs — violations, penalties
Legal information, not legal advice. Verified as of October 2026. Applying it to a particular situation is the work of a licensed Missouri attorney.