Chapter 11

Driving on Expressways

Classification of Highways 16.1

Three Classifications of Highway Systems

◦ 1. Interstate Highway System Controlled access: vehicles can enter and leave only at

designated interchanges.

Interchanges: places where drivers can cross over or under

traffic as well as enter or leave the freeway.

Freeways: multi lane divided highways designed for high

speeds. (at least 2 lanes)

Traffic is separated by grade elevation.

Grade elevation: bridges and tunnels are used to direct

traffic over or under other travel lanes.

May have tolls.

“Free” ways = without traffic lights

Even numbers run east a

and west beginning in the south

Odd numbers run north and

south beginning on west coast

Expressways◦ May have

non-controlled

access. (Could

have traffic lights,

intersections,

and driveways)

◦ Distraction could lead to greater risk of rear-ending the vehicle

ahead or of being rear-ended by others.

Turnpikes and Parkways

Turnpike- use to designate a toll road but may no

longer charge tolls.

Parkways- may have a stop sign at the end of the

entrance ramp and no acceleration lane. May have

traffic lights.

◦ Commercial traffic and billboards are prohibited.

U.S. Highways

◦ Connects state to state

◦ Non-controlled access

◦ Intersections with traffic controls to separate crossing traffic.

• State Highways

• Within the boundaries of the state

• Most are narrow two-lane roadways in rural areas

• Some may be expressways or controlled access freeways

Freeway Interchanges

Cloverleaf

Series of

entrance and

exit ramps that

resembles a four

leaf clover.

Proceed in either direction on either

highway.

Diamond

Used when a

road that

crosses a busy

highway has

little traffic.

Trumpet

Used where

one highway

forms a T-

Intersection

with a freeway

All directional interchange◦ Used in

complicated intersection

With high-volume traffic.

channeled in many

different directions.

Entrance Ramps

Entrance ramps provide one-

way directional access to an

expressway.

Merging

area

Acceleration

lane

Enterance

Ramp

The ramp is divided into three sections:

1. The Entrance or Access Ramp — gives the

driver time to begin evaluating traffic

conditions.

2. The Acceleration Lane — allows a driver

to adjust vehicle speed to the speed of

traffic on the expressway.

3. The Merging Area — allows the driver to

merge onto the expressway.

Entering the Entrance Ramp

Entrance

Ramp

Enter the Entrance Ramp

Begin Searching for a Gap /

Open Space

Identify Gap / Space

Entrance

Ramp

The entrance ramp

◦ Never back up on entrance ramp

◦ When other vehicles are on the entrance

ramp, adjust your speed to 3 or more seconds

of space.

Hole in traffic

◦ An empty space between traffic clusters.

Ramp Metering

Used to control large volumes of traffic entering

expressways

Uses a system of lights and sensors

Allows only a few cars at a time to enter

congested limited access highways

Acceleration Lane

Acceleration Lane

Use the left-lane signal indicator

Adjust speed to match the speed

of the traffic on the expressway

Monitor gap on expressway

Acceleration Lane

Entering Merge Area

Accelerate to blend with the speed

of traffic on the expressway

Check Rear and Left Rear Zones

Merge

Area

Selecting a Gap in Traffic

Merge Area

Check Front Zone

Check Rear and Left Rear Zones

Select Gap

Signal and glance over left outside mirror

and left shoulder

Identify a Target Area in the Open Space

Increase speed for a smooth merge

Adjust your speed to match the traffic flow

Cancel your signal & have 3 sec follow dist.

Target

Area

Strategies for Driving on Highways

Applying the IPDE Process and Zone Control◦ Identify: visual information from farther ahead, closed

front zones. Don’t become trapped between two large vehicles.

◦ Predict: Search for slower traffic or drivers changing lanes and anticipate closed zones and points of conflict.

◦ Decide: Driving speeds on highways demand that you make quicker decisions.

◦ Execute: Signal early and maintain 3 seconds following distance.

Choosing Lanes at Exit or Entrance

Center Lane:

Long distance or passing

Heavy traffic in right lane

Left Lane:

Higher speed and passing traffic

Trucks and towing trailers restricted

Exit / Entry

Right Lane

Center Lane

Left Lane

Right Lane:

Heavier and slower vehicles

Vehicles entering the expressway

Vehicles getting ready to exit

When following large trucks or buses

When following motorcycles

When driving in bad weather

When being tailgated

When driving with a heavy load or pulling a trailer

When entering/exiting the expressway

INCREASE

Lane choice◦ Scan signs quickly and frequently.

Overhead sign with a yellow panel

indicates the exit lane. All traffic

must exit.

Reversible lanes◦ Traffic can travel in either direction depending on certain

conditions.

◦ Used during commuter

hour where traffic in and out

of city is heaviest.

High Occupancy Vehicle(HOV) lanes

◦ For buses and vehicles that have tow or more

occupants.

◦ Ex. Arizona & California

High Occupancy toll (HOT) lanes

◦ Drivers pay a fee in order to drive in an HOV

lane with only one person in the vehicle.

When Changing Lanes

Weaving from lane to lane can lead to collision.

Conflict created when two drivers head for same space

at the same time from opposite sides after passing a

vehicle.

Remember exit ramps can be on the left side.

Closed roads for construction.

Illegal to use shoulder or median as a driving lane in

traffic.

When Being Passed

Monitor passing vehicle’s position.

Move to lane position 3 to increase space cushion

Do not increase speed when being passed —

decelerate if necessary

Once passed, create space ahead and behind

move away

Passing

Before you pass, evaluate the zone and signal.

Check blind spot to the left or right.

Passing on left is best.

Passing on right can be dangerous because it is less expected and peripheral

vision is less effective than their central vision.

Exit

Ramp

Deceleration Lane

1. The Deceleration Lane — an

added lane where it’s safe to

slow your vehicle without

blocking the vehicles behind

you.

2. The Exit Ramp — the ramp

leading off the highway.

Pay attention to the exit ramp

speed

Applying the IPDE Process at exits

Identify the green guide signs that

show the distance to your exit

Identify any potential weave pattern

before you reach your exit

Identify closed and open zones

Predict actions of other drivers who

might be using the same exit

Decide on the best speed and lane

position before getting in the

deceleration lane.

Execute your maneuver smoothly and

blend with slower traffic

Exiting the Expressway

Exit

Ramp

Deceleration Lane

Deceleration Lane

Signal

Maintain speed while on the expressway

Use mirrors to check behind and to the sides

Check mirror blind zones

Move into deceleration lane

Prepare to decelerate quickly

Adjusting Exit Speed

Deceleration Lane

Exit

Ramp

Brake to Warning Sign Speed — Check

Behind

Scan New Path of Travel to the Front

Search for Traffic Control Signs or Signals

Highway Hypnosis

Is a dulled or drowsy condition that can occur when driving long distances

Situation becomes worse when the driver’s eyes focus on the center line.

Plan breaks and rest stops to combat highwayhypnosis or go to a safe area for rest or sleepwhen tired.

Expressways through cities

• Avoid driving in the right lane when

vehicles are merging

• Search for signs, signals, and roadway

markings

• Search for exits early and adjust position

in adequate time to exit safely

• Don’t make last minute lane changes to

gain access to an exit

• Monitor the zones around your vehicle

and adjust position to create space

cushions

Disabled vehicles

• Check rear zones, signal, and move

as far away from traffic possible

• Turn hazards on

• Never stand in the highway

• Remain in vehicle, lock doors, call

for help.

Special Roadway ConditionsConstruction areas

Use caution when approaching:

Search ahead for warning signs.

Reduce your speed.

Adjust position to maintain a space around your vehicle.

Toll booths

Exact change booths — The driver deposits

coins (exact change) into a machine.

Attendant operated booths — For large vehicles

or drivers without exact change.

Electronically operated booths — For drivers

with prepaid accounts (IPass).

When exiting a toll-booth plaza,

search traffic to both sides for open

space, accelerate smoothly, and

adjust speed to blend with the flow of

traffic.