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Things to Remember about Interstate Highway Driving

Interstate Highway Driving -

What You Must Know about Interstate Highway Driving

When you practice for your permit test and the DMV written test you should pay special attention to information about driving on interstates and controlled-access highways. Questions about interstate highway driving are very likely to show up on your DMV written test, no matter if you are a first-time permit applicant or just taking a re-examination.

Unlike what most people think, driving on controlled-access highways is usually safer than driving on other highways. There are fewer places on an interstate that can cause crashes. As an example, crossings and intersections don’t exist. When accidents do happen, they are, however, often more serious. Mainly because of the high speed.

That is one reason why most States put extra emphasis on safe interstate highway driving in their driver’s manual and on the written DMV test.

Your Speed when Entering an Interstate Highway

You enter an interstate by using an entrance ramp, and very often, an acceleration lane. The purpose of the acceleration ramp is to help you get up to speed.

Interstate Speed -

Let us take a look at this question, which is pretty common on tests:

What should your speed be when entering an interstate highway?

  A. Same as the interstate traffic.
  B. Same as the legal speed limit.
  C. Faster than the interstate traffic.
  D. Slower than the interstate traffic.

The correct answer is A. Your speed when entering an interstate highway should match the flow of traffic, keeping in mind that you must not exceed the posted speed limit. B is incorrect, since the traffic isn’t always moving at this speed. Weather, visibility or other circumstances may force traffic to move well below the speed limit.

Looking for a Gap when Entering an Interstate Highway

While you are getting up to speed on the acceleration lane, check over your shoulder for a gap between vehicles in the lane you want to enter. Don’t assume that over drivers will move over and give you space to merge smoothly.

Interstate Highway Driving -

Make sure your gap gives you a big enough space cushion. Your gap should be at least four seconds. Don’t try to merge into a gap that is too small. A small gap can quickly become even smaller.

When you see a gap, signal your lane change before you start to merge.

If you don’t see a gap, slow down and wait. Don’t forget that traffic on the interstate has the right-of-way. Trying to merge when there is no space can be extremely dangerous. Other drivers may not see you.

You should also avoid driving to the end of the acceleration lane and stop – if at all possible. If you stop you will not be able to get up to interstate speed and merge smoothly.

Safe Speed on the Interstate

On the interstate, you should keep pace with other traffic without exceeding the speed limits. Driving much slower than other traffic is dangerous. The chance of a crash is very high whenever the difference between your speed and the speed of other traffic is more than 15 mph.

Look at the following question:

You are driving on a freeway posted for 65 mph. Around you, traffic is traveling at 70 mph. What should your speed be?

  A. Faster than 70 mph.
  B. 70 mph to keep up with traffic.
  C. No faster than 65 mph.
  D. Between 65 and 70 mph.

Correct answer is C.

Even if the flow of traffic exceeds the speed limit, you shouldn’t! The speed limit is there for a reason. In bad conditions, you must drive slower than the speed limit (basic speed law).

Safe Following Distance on the Interstate

Always keep a safe following distance to the vehicle ahead of you. Be alert for large vehicles and motorcycles. Increase your following distance when needed. If visibility is reduced or pavement is wet, always double or triple your following distance. Remember that rear-end crashes are the most frequent type of crashes on Interstate highways. Don’t be a tailgater!

You should also keep space cushions to the sides by driving in the middle of your lane and avoid driving in another driver’s blind spot.

Safe Passing on the Interstate

Keep in the right-hand lane, unless you need to pass other vehicles. If another driver wants to merge in front of you, be courteous and fall back to let them enter your lane smoothly. Adjust speed and following distance as needed.

When you pass and overtake other vehicles, pass with caution. Always signal and check your blind spots before making lane changes. Avoid lingering beside the other vehicle when you pass. Pass as quickly as possible, and always on the left-hand side. Before pulling back in, make sure you can see the front of the vehicle you are passing in your rear-view mirror. Allow for some extra space before pulling back in front of a large vehicle.

Important Reminders

The following are some more reminders for your written DMV test (questions that could show up on your exam):

You must NEVER back up on the interstate. Should you miss an exit, always continue to the next one.

NEVER park on the shoulder of an Interstate, unless your vehicle breaks down or there is another emergency. In such a case, stop well off the roadway and make sure others can see you. Turn on your emergency flashers, raise the hood/trunk, and use a white cloth to signal your emergency.

NEVER cross the median of an interstate highway, unless an opening has been provided and signs tell you that crossing is allowed.

If you are driving long distances, take a break every two hours and whenever you feel drowsy. Fatigue is a real danger on interstate highways.

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  1. When entering an interstate, DMV says to do the speed the traffic is doing…..but don’t exceed the speed limit. If the traffic is doing over the posted speed limit….we do what the traffic is doing….but we’re not supposed to go over the posted speed limit. Contradictory there, folks.

    • This “contradiction” is rarely a problem in real life. In heavy traffic when finding a gap can be difficult, the flow of traffic is usually within the speed limit or slower. Should the flow of traffic exceed the speed limit, there are usually plenty of gaps, and other drivers tend to move over to the left to let you merge smoothly. So accelerating to (or near) the speed of traffic and at the same time staying within the posted limit is often no problem.

      • You clearly haven’t lived in Houston or Dallas, then. The flow of traffic is ALWAYS a minimum of 10-15 (or more!) of the posted speed limit, even with five lines of bumper-to-bumper traffic. Unless, of course, there is a wreck. Best way to get yourself killed is to do the speed limit. So, not so rare, as I’ve seen this in many other places, as well. Don’t believe me? Try I-10 E across Louisiana sometime.

      • Lived the last 10 years in Dallas. Use Dallas North Tollway, Central Expressway, and 121 on a regular basis. I never had any problem entering any of these and keeping the speed limit during rush hour or otherwise.

        There is no statistical support for your statement that driving at the speed limit will get you killed. And encouraging new drivers to speed up above the speed limit when entering a highway is simply irresponsible.

  2. its a good driving test

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  4. Shouldn’t you always pass other vehicles on the left-hand side? Isn’t the left lane the passing lane?

    • Yes, absolutely. You should pass on the left side whenever possible. Passing on the right is normally allowed on multi-lane highways, but other drivers may not always expect you to pass on their right-hand side.

      Unfortunately, the text originally said right-hand side – it is now corrected.

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