Fitness to Drive, Steering, Signals, Headlights, Lane Markings and Lanes

Written for aiforu2 as the source for a practice-test bank and the on-device tutor for the California Class C knowledge test. The facts follow the official handbook; the wording is ours.

Source: California Driver's Handbook (DL 600), California Department of Motor Vehicles, 2025 edition, section 5 "An Introduction to Driving" (pp. 9–12) and section 6 "Navigating the Roads", first part (pp. 13–17).

Your health and driving

Vision: you must spot hazards in every kind of light, judge distances, adjust to traffic speed and read signs. Hearing: you must be able to hear horns, sirens, motorcycles and screeching tires; wearing a headset or earplugs in both ears while driving is illegal. Fatigue blurs vision and lengthens reaction time. You must be alert enough to decide quickly in unexpected situations. Medications, prescription or over-the-counter, can make you sleepy or unsafe, and it is your responsibility to know their effects. Physicians must report patients aged 14 or older to DMV for conditions that may affect safe driving, such as a lapse of consciousness.

Steering

Keep both hands on the wheel whenever possible.

• Hand-to-hand (push/pull): hands at 9 and 3 or 8 and 4 o'clock; never cross your hands over the middle of the wheel; keep the positions even in turns.
• Hand-over-hand: for low-speed turns, parking and recovering from a skid. Start at 8 and 4, reach across to grip the far side, release the other hand, reach across that arm, grip and pull up.
• One hand: only when backing up while turning to look behind (hand at 12 o'clock), or when operating a control that needs a hand off the wheel.

Signaling

Signal whenever you turn, change lanes, slow down or stop, with the signal lights or with hand-and-arm signals when the lights fail or bright sun hides them: left arm straight out for a left turn, bent up for a right turn, bent down for slow or stop. A bicyclist may signal a turn with either arm held straight out toward the turn. Signal at least 100 feet before a turn, before every lane change, at least five seconds before a freeway lane change, before pulling to or from the curb, even when no one seems to be around, and when you are almost through an intersection if you will turn just after it. Cancel the signal when done.

Horn and headlights

Use the horn to let others know you are there or to warn of a hazard: to avoid a collision, and on narrow mountain roads where you cannot see 200 feet ahead.

Headlights help you see and help others see you. Dim high beams within 500 feet of an oncoming vehicle and within 300 feet of a vehicle you follow. Driving with only parking lights is illegal. Use headlights when it is too dark to see 1,000 feet ahead, from 30 minutes after sunset until 30 minutes before sunrise, in bad weather (whenever you need the wipers for fog, rain or snow, the low beams must be on), when clouds, dust, smoke or fog hide other vehicles, on mountain roads and in tunnels even on sunny days, where a sign requires them, and when the sun is low so others can see you.

Emergency flashers

If you see a collision or hazard ahead, warn drivers behind you: turn on the flashers, tap the brake pedal three or four times, and use the slowing hand signal. If you must stop for vehicle trouble: flashers on (or the turn signals if you have none), pull off the road away from traffic if possible, and otherwise stop where you can be seen from behind; never stop just over a hill or around a curve; call roadside assistance and stay in the vehicle until help comes.

Lane markings

• Single solid yellow line: the center of a two-way road. Do not pass when there is one lane in your direction and the solid yellow is on your side.
• Double solid yellow lines: do not cross, except in an HOV lane with a designated left entrance, when construction signs send you to the other side because yours is closed, or when turning left across a single set into or out of a driveway or private road or to make a U-turn.
• Two sets of double yellow lines two or more feet apart are a barrier: never drive on or over it, turn left or U-turn across it except at designated openings.
• Broken yellow line: you may pass when the broken line is next to your lane and it is safe.
• Single solid white line: separates lanes going the same direction, including on one-way streets.
• Double solid white lines: a barrier between a regular lane and a preferential lane such as an HOV lane, also seen near freeway ramps. Never change lanes across them; wait for a single broken white line.
• Broken white lines: separate lanes on roads with two or more lanes in the same direction.
• End-of-lane markings: large broken lines mark a lane that is ending or becoming an exit; be ready to exit or merge and look for the sign.
• Yield line: a row of solid white triangles pointing toward you shows where to yield or stop.

Choosing and changing lanes

Lanes are numbered from the left: the far-left (fast) lane is the Number 1 lane, the next to its right the Number 2 lane, and so on. Use the left lane to pass or turn left, the right lane to enter or exit traffic or when coming from a curb or shoulder. Before a lane change: signal, check the mirrors, check traffic behind and beside you, look over your shoulder toward the new lane, check blind spots for cars, motorcyclists and bicyclists, do not drift, and make sure there is room; you do not need to slow down first. Stay in one lane as much as possible and never weave. Once you start through an intersection, keep going; once you start a turn, follow through; if you miss a turn, keep going until you can turn around safely and legally.

Types of lanes

• Passing lane: on a multilane road, the far-left lane next to the center divider.
• Carpool / HOV lane: reserved for carpools, buses, motorcycles and low- or zero-emission vehicles with a DMV decal. Signs at the on-ramp or along the road give the minimum number of occupants and the hours. The pavement shows a diamond and the words Carpool Lane. Enter and exit only at designated openings, never across the double solid lines.
• Center left-turn lane: in the middle of a two-way street, marked on each side by a broken inner line and a solid outer line. Use it only to prepare for a left turn or U-turn; it is not a travel or passing lane, and you may drive in it for no more than 200 feet. Watch for vehicles coming toward you in the lane, signal, check over your shoulder, merge completely into the lane so you do not block traffic, and turn when safe.
• Turnout areas or lanes: on two-lane roads, pull into them to let traffic behind you pass. You must use one when you are driving slowly where passing is unsafe and five or more vehicles are following you.
• Bicycle lanes: for bicyclists only, usually marked by a solid white line and sometimes painted green. It is illegal to drive in one except to park where allowed, to enter or leave the road, or to turn within 200 feet of an intersection; check your blind spots first. Variants include the buffered bike lane (chevrons or diagonal markings for extra separation), the bike route (signs and shared-road markings), the bicycle boulevard, the separated bikeway or cycle track (posts, curbs, barriers or parking between bikes and cars), and shared roadway markings ("sharrows") that tell drivers a bicyclist may use the lane. Give a bicyclist three feet of space. A motorized bicycle in a bike lane must go at a reasonable speed and not endanger other riders.

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