Chapter 16
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
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
Expressways
◦
May have
non-controlled
access. (Could
have traffic lights,
intersections,
and driveways)
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.
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
Freeway Interchanges
Cloverleaf
Series of
entrance and
exit
ramps that
resembles a four
leaf
clover.
Diamond
Used when a
road that
crosses a busy
highway has
little
Trumpet
Used where
one highway
forms a
T-Intersection
with a
All directional interchange
◦
Used in
complicated intersection
With high-volume traffic.
channeled in many
Entrance Ramps
Entrance ramps provide one- way directional access to an expressway.
Merging area Acceleration lane Enteran ce 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.
Entering the Entrance Ramp
Entrance Ramp
Enter the Entrance Ramp
Begin Searching for a Gap /
Open Space
Identify Gap / Space
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
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
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
Entering Merge Area
Accelerate to blend with the speed of traffic on the expressway
Check Rear and Left Rear Zones
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
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.
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
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
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
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
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
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
Passing
Before you pass, evaluate the zone and signal.
Check blind spot to the left or right.
Passing on left is best.
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
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
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
Adjusting Exit Speed
Deceleration Lane Exit
Ramp
Brake to Warning Sign Speed — Check
Behind
Scan New Path of Travel to the Front
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.
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
Special Roadway Conditions
Construction 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
