Speed Limits

Illinois Rules of the Road: Lane Usage

Illinois laws regulate and detail how drivers are supposed to act in traffic. These are so-called “Rules of the Road“, part of which explains how to properly,¬†lawfully and safely use lanes.

Drivers must drive on the right half of the roadway except:

  • When passing another vehicle moving in the same direction on a two-lane highway, interstate highway or controlled freeway.
  • When a blockage makes it necessary to drive to the left of the center line. Drivers may drive on the left after yielding to oncoming traffic.
  • On a roadway divided into three marked lanes for traffic.
  • On a one-way street with two or more lanes of traffic.
  • When directed to drive in a left lane by traffic control signs and signals on a multilane, two-way highway.
  • When crossing the center line to make a left turn into or from an alley, private road or driveway.
  • When approaching a stationary emergency vehicle.
  • When roadway construction is located in or in close proximity to the right lane or right shoulder.

When driving on an interstate highway or full access controlled freeway, a driver may not drive in the left lane(s), except when passing another vehicle. Exceptions include when:

  • No other vehicle is directly behind the vehicle being driven in the left lane.
  • Traffic conditions/congestion make it impractical to drive in the right lane.
  • Weather conditions make it necessary to use the left lane(s).
  • There is an obstruction or hazard in the right lane.
  • The driver is changing lanes to yield to emergency or construction vehicles.

Additional rules apply in certain situations:

  • Slow vehicles must use the right-hand lane except when passing vehicles or making a left turn.
  • Weaving from lane to lane to move faster than the traffic flow is unlawful.
  • Traffic must travel in the direction of posted one-way streets or roadways. This rule does not apply to police and emergency vehicles using sirens or flashing lights.
  • It is unlawful to drive across median strips such as unpaved strips or median barriers. A driver may turn left across a paved dividing-space unless it is not permitted by a traffic control sign or signal.
  • A driver must not enter or leave any controlled-access roadway except at a posted entrance or exit.
  • A driver may not back up on any shoulder or roadway of any controlled access roadway.
  • A driver may not back up on other roadways unless it is done safely and does not interfere with other vehicles.
  • A driver or passenger may not open doors on the side of a vehicle on which traffic is moving unless it can be done safely and without interfering with traffic. The door may remain open only long enough to load or unload passengers.
This article about Illinois Rules of the Road: Lane Usage was last updated in 2024. If any of our information is incomplete or outdated please let us know. Thank you!