Idaho · Handbook chapter 6 · 3 min read

Planning a freeway trip, using the entrance ramp, acceleration lane and merge area, Idaho interstate speeds, lane use, median crossovers and leaving the freeway.

Why this chapter matters

Freeways are among the safest roads, but their speeds mean one mistake can be disastrous, and boredom and fatigue creep in. The test asks how to merge, which lane to use and what to do if you miss an exit. Learn five seconds and half a mile.

Before you go

Plan food, rest and fuel stops on long trips, and know your route, entrance and exit numbers on short ones. Tell someone your route and when to expect you.

Entering a freeway

A freeway entrance has three parts: the entrance ramp, the acceleration lane and the merging area.

1. Make sure the ramp is the one you want. If you take the wrong one, never back up or turn around through the median; go on to the next exit.
2. On the ramp, check traffic, signal and look over your left shoulder for a gap.
3. In the acceleration lane, speed up to the speed of freeway traffic so you can blend in.
4. Yield to traffic already on the freeway, merge into the gap, then cancel your signal.

On short ramps or in heavy traffic you may have to slow before the end of the acceleration lane, or even stop. If you stop, leave room ahead so you can build up speed, wait for a big enough gap, signal and accelerate quickly.

Speed and lanes

• Where designated and weather allows, speeds may reach 80 mph on rural interstates and 65 mph on urban interstates, unless posted otherwise. A minimum speed may also be posted. If you cannot keep up, use another road.
• Keep a steady speed with the flow of traffic.
• Drive mostly in the right or center lane. The left lane is for faster traffic and passing.
• In rush hour, stay out of the right lane where you can, to leave room for entering drivers.
• Signal for at least five seconds before changing lanes or exiting.

Medians and crossovers

It is illegal to drive across a median or unpaved dividing strip except at an authorized opening. On interstates, median crossovers are only for emergency and maintenance vehicles.

Leaving the freeway

• About half a mile before your exit, signal and move to the lane nearest the exit.
• Signal again and move into the deceleration lane to slow down without slowing the traffic behind you.
• Obey any posted exit speed on the ramp.
• Be ready for busier, slower and more complicated traffic once you leave the ramp.