Space to merge — Montana Permit Test

You need a gap of about four seconds whenever you merge, change lanes, enter a roadway, or your lane merges with another.

Squeezing into a short gap leaves both you and the car behind too close to stop.

You need a gap of about four seconds anytime you want to merge with other traffic.

If you move into the middle of a four-second gap, both you and the vehicle now behind you have a two-second following distance.

A driver who thinks a four-second gap leaves four seconds each forgets they split it.

If you move into the middle of a four-second gap, both you and the vehicle that is now behind you have a two-second following distance.

Do not try to merge into a gap that is too small, because a small gap can quickly become even smaller.

The car behind the gap speeds up just as you cut in, and the gap is gone.

Do not try to merge into a gap that is too small.

If you want to cross several lanes, take them one at a time; waiting until all the lanes are clear can tie up traffic and even cause a crash.

A driver darting across three lanes at once cannot check them all and cuts off someone.

If you want to cross several lanes, take them one at a time.

About how large a gap do you need to merge with other traffic?

4 seconds. Squeezing into a short gap leaves both you and the car behind too close to stop. Montana Driver Manual, p.66: “You need a gap of about four seconds anytime you want to merge with other traffic.”