Knowing the rules of the road

How to properly use a roundabout

Now that the opening of the Granite Drive interchange on Hwy 101 is imminent, Valley residents will have three new roundabouts to contend with.

And, with public knowledge on how to properly use a roundabout sorely lacking, here is a complete guide.

First, let’s start with some simple rules. A roundabout is an intersection control device just like traffic lights. You must signal your turns and you must be in the appropriate lane to complete your turn. You can never change lanes within the roundabout. Traffic already in the roundabout has the right of way over traffic approaching or entering the roundabout.

Roundabouts save gas and reduce emissions by eliminating idling at traffic lights.

Mathematically, roundabouts are safer. At an intersection controlled by traffic lights there are 32 different points where two cars can collide - at roundabouts there are only four.

Roundabouts (when used correctly) enhance the flow of traffic.

Now let’s examine the Granite Drive-Commercial Street roundabout more closely. This is a two-lane roundabout. That means that there are two lanes entering the roundabout, two lanes in the roundabout (two cars can be side- by-side in the roundabout,) and two lanes exiting the roundabout.

Both lanes entering the roundabout can continue straight through the roundabout. The car entering the roundabout in the right lane must use the right lane in the roundabout and exit into the right lane leaving the roundabout. The car in the left lane must use the left lane in the roundabout and exit into the left lane leaving the roundabout.

More specifically, if you are making a right turn you must be in the right-hand lane and your right turn signal must be activated. If you are making a left-hand turn, you must be in the left-hand lane and your left turn signal must be activated.

Drivers wishing to make a left turn (or make a U-turn) at the roundabout must move into the left lane prior to entering the roundabout. As they approach the roundabout they must engage their left turn signal.

This is a significant departure from the normal rules of the road where left-turning traffic must yield to all oncoming traffic. At a roundabout, left-turning traffic has the right of way over traffic that has not yet entered the roundabout. The yield sign at the entrance to the roundabout confirms this.

You must also always use your turn signal to indicate the point at which you are exiting the roundabout.

Drivers must slow down as they approach the roundabout to better determine if it is necessary to stop and yield to traffic in the roundabout. You will only have to yield to traffic approaching from the left. Drivers that are following the rules of the road will have their turn signals activated. This makes it easy to determine which drivers will be coming across your path (and have the right of way) as they use the roundabout.

When it is safe to do so, enter the roundabout and, for left turns, use the left lane to move around the roundabout in a counter-clockwise direction. As you’re going around the roundabout you will pass the place where you might have made a right turn, you will pass the place where you might have gone straight and then, finally, staying in the left lane you exit the roundabout into the left lane of the road you are turning onto.

It is important, as stated above, that you signal to exit the roundabout. During a left turn, as you pass the place where you might have exited the roundabout to go straight, you must switch your left-turn indicator off and engage your right-turn indicator to let traffic know you are not continuing further around the roundabout.

Vehicle operators who clearly indicate their intentions by proper activation of their turn signals are enhancing the roundabout’s efficiency to handle traffic.