Expressways

Sessions 25-28 focus on complex risk driving environments with speeds up to 70 mph. Traffic flow on expressways can be heavy and at times unpredictable. They are called limited or controlled access highways because there are only certain locations, called interchanges, where a driver can enter and exit the expressway. Expressways have a low frequency of collisions, but often have high injury severity rates when a crash does occur because of the higher speeds.

Review the expressway information in the DDS driver’s manual. Make sure your teen understands the different kinds of expressway interchanges, expressway signs, signals, lane markings, speed limits, and the importance of maintaining a 20-30 second visual lead.

Entering an expressway – expressway entrances include three areas: the entrance ramp, the acceleration lane, and the merge area. The entrance ramp allows the driver time to search the expressway and evaluate speed and available space before entering. Entrance ramps may be uphill, downhill, or level with the expressway. Each of these roadway conditions presents a different challenge when trying to search the traffic flow on the expressway. Using commentary driving, have the teen practice entering and exiting the expressway 10 times during each session.

Steps for Entering the Expressway:

• Check for ramp speed signs;
• On the entrance ramp, search for vehicles ahead and behind on the expressway using quick glances while searching for gaps or open spaces in the traffic flow;
• In the acceleration lane, use the signal to indicate your desire to enter the expressway, and adjust speed to the flow of traffic;
• Avoid the gore;
• From the merge lane, enter the gap in the flow of traffic;
• Release turn signal;
• Establish a new target area.
  

Steps for Exiting the Expressway:

• Identify the exit well in advance;
• Move into the lane closest to the exit;
• Check traffic to the rear; do not reduce speed on the expressway;
• Avoid the gore;
• Signal intentions 4-6 seconds in advance of the ramp;
• Enter the exit ramp, tap brakes and rapidly begin reducing speed;
• Continue decelerating to the posted speed before entering the curve on the ramp.

Expressway Driving Tips

• Adjust the vehicle’s position and speed to road and weather conditions.
• Maintain a minimum 4 second following interval when merging onto the expressway, changing lanes, and exiting the expressway.
• Minimal steering inputs are needed at higher speeds to change lanes, enter, or exit the expressway; excessive steering can easily lead to a loss of control at higher speeds.
• Make room for vehicles entering the expressway from an entrance ramp by moving out of the lane next to the merging area.
• Always move over one lane at a time when moving across multiple lanes.
• Be alert for crosswinds when driving on bridges or through open mountain passes.
• When another driver tailgates, increase your 4 second following interval and, if possible, change lanes.
• When driving over a long period of time, be aware of a condition known as “highway hypnosis.” This results in driving in a dulled, drowsy, trance-like condition.

Route Numbering

Most routes are one- and two-digit numbers.

• North-south routes have odd numbers.
• East-west routes have even numbers.
• The greater the even number, the farther north the road is in the United States.
• The greater the odd number, the farther east the road is in the United States.
• Exit numbers correlate with mile marker numbers.

Alternate routes are usually three-digit numbers, with the last two numbers designating the main one- or two-digit route.

• If the first digit is even, the alternate route is a loop that goes around a city.
• If the first digit is odd, the alternate route goes into a city.

Ramp Metering

Ramp Meters are traffic signal devices located on entrance ramps to the freeway. The Ramp Meter Program was implemented to alleviate congestion and emphasize motorist safety. The meters regulate the frequency of vehicles entering the flow of traffic on a freeway. They work similar to traffic signals with a red and green light. All vehicles must stop when the light is red. Vehicles are only permitted to move onto the freeway when the signal turns green.