Lane Use, Pavement Markings, Overtaking and Passing

Lane Use, Pavement Markings, Overtaking and Passing

Quick Answer: Yellow lines divide two-way traffic; white lines divide lanes moving the same direction. You may pass only where the broken line is nearest your side of the road. Passing on the right is lawful in only three situations, and Guam's wide paved shoulder is not one of them: the legally traveled roadway ends where the solid white line on your right begins. While passing, never get closer than 100 feet to an oncoming vehicle.

Keep right, and stay in your lane

Drive on the right half of the roadway, with four exceptions: when overtaking and passing another vehicle going the same direction, when placing the vehicle in a lawful position for a left turn, when the right half is closed to traffic, and on a roadway signposted for one-way traffic (Sec. 3309(a)). More specifically, drive in the right-hand lane or as close as practicable to the right-hand edge or curb, except when overtaking and passing or when preparing for a left turn at an intersection or into a private road or driveway (Sec. 3310).

Trucks, tractors, trailers, or combinations with a gross weight of vehicle and load of 10,000 pounds or more may not be driven in the farthest left-hand lane, except to overtake and pass, to prepare for a left turn, or when the road has a single lane (Sec. 3312).

Where a roadway is divided into three or more clearly marked lanes (Sec. 3314):

• Keep the vehicle as nearly as practical entirely within a single lane, and do not move out of that lane until you have first made sure the movement can be made with safety.
• Never change lanes in an intersection.
• On a three-lane road, the center lane may be used only to overtake and pass where the roadway ahead is clearly visible and the center lane is clear of traffic within a safe distance, in preparation for a left turn, or where the lane is signposted as allocated to traffic moving your direction.

Pavement markings on Guam

The handbook lists four marker colors in use: white, yellow, red, and blue. The two whose meanings you are tested on are:

A local fact worth remembering because it shows up in Guam-specific items: small reflective markers are used more than paint on Guam to indicate these markings, because paint does not last long here. In practice the line you are steering by is often a row of raised reflectors rather than a painted stripe, which is exactly why they still read at night and in heavy rain. (The handbook lists red and blue among the marker colors without defining them, so do not invent a meaning for those two on the exam.)

The line rules that govern passing are three:

1. Where a highway is divided by a solid white or yellow line, no vehicle may cross over it or drive to the left of it, except to turn left at an intersection or into or out of a driveway or alley, during a lawfully allowed U-turn, or where signs authorize the use of off-center traffic lanes.
2. Where a solid line runs alongside a broken line, you may pass only if the broken line is nearest your side of the road. If the solid line is on your side, you may not pass.
3. Where only a broken line separates the lanes, vehicles going in both directions may pass when the way ahead is clear.

Overtaking on the right

Sec. 3317 permits passing on the right in exactly three situations, and then only under conditions permitting the movement in safety:

1. The vehicle being overtaken is making or is about to make a left turn;
2. The highway has unobstructed pavement of sufficient width for two or more lines of vehicles in each direction;
3. The highway is one-way.

Two riders travel with the rule. A slow-moving vehicle is never relieved of its duty to drive as closely as practicable to the right-hand edge of the roadway (Sec. 3317(c)). And you may never pass on the right on a two-lane highway at an intersection, a maneuver the handbook calls out by name and that is normally posted with NO PASSING signs.

The shoulder trap. Guam has many stretches of exceptionally wide paved shoulder lane, and drivers treat them as an extra lane. The handbook forecloses it: the legally traveled portion of the roadway ends where the solid white line on your right begins, and the shoulder lane is NOT for passing. In a business or residential district where the pavement is wide enough for two or more lines of vehicles moving your direction, you may pass on the right or the left when conditions are safe, but you must never drive off the paved or main traveled part of the roadway to do it.

Overtaking on the left

You may not drive to the left of the center line to overtake unless that left side is clearly visible and free of oncoming traffic for a sufficient distance ahead to complete the pass without interfering with the safe operation of any vehicle approaching from the opposite direction or of the vehicle being overtaken (Sec. 3318(a)). Beyond that judgment call, you may never drive to the left side of the roadway:

• When approaching the crest of a grade, or on a curve, where your view is obstructed within a distance that would create a hazard if a vehicle came from the opposite direction;
• On a three-lane highway.

Those limitations do not apply on a one-way roadway (Sec. 3318(c)).

The 100-foot rule. Get back to the right side early: never get closer than 100 feet to an oncoming vehicle during a pass. Run the arithmetic once and the rule stops feeling arbitrary. At 45 mph, Guam's maximum lawful speed anywhere on the island, you cover 66 feet every second. If the oncoming car is also doing 45, the gap between you closes at 132 feet per second, so a pass that takes 8 seconds to complete eats more than 1,000 feet of closing distance. On a two-lane road with a bend or a rise in it, that much clear sight distance usually is not there, which is why the honest answer to most passing questions on this exam is "wait."

Do not cut in. After passing at a safe distance to the left, return to the right lane only when you can see the passed vehicle in your rear-view mirror and are certain you are safely clear of it.

If you are the one being passed, give way to the right in favor of the overtaking vehicle and do not increase your speed until you have been completely overtaken and passed (Sec. 3319). The handbook states the driver's duty as maintaining the same rate of speed, unless an emergency requires slowing to prevent a collision.

Before any lane change, left or right, signal first so drivers ahead of and behind you know your intention, then turn your head both ways and look. Never make the change until you are sure the lane is clear, and never rely on the rear-view mirrors alone.