Sharing the road
The large truck ahead of you swings out to the left as it comes up to a corner. What is the safest reading of that move?
- It may be swinging wide in order to turn right; check its turn signals before you pass. Correct answer
- It must be turning left, because a vehicle's rear wheels follow a wider path than its front wheels.
- It is drifting; close up behind it so you are clear of the swing.
Why
Long vehicles corner in two movements. Because the back wheels cut a tighter arc than the front ones, and the longer the vehicle the bigger that gap, a truck often has to swing the opposite way first to get around, which is why one drifting left can be about to turn right. The handbook's instruction is to look at its turn signals before you start to pass, not at the body of the truck. The answer that has the rear wheels tracking wider than the front has the geometry the wrong way round. Closing up behind it is wrong twice over: following too closely decreases your safety distance, and if you cannot see the truck's side mirrors the driver cannot see you.
Where this comes from
California Driver's Handbook, June 2025 edition. The correct answer is It may be swinging wide in order to turn right; check its turn signals before you pass.
The rule behind this one
Sharing the road in California goes through the whole topic, with the page of the California Driver's Handbook behind every rule.
More on sharing the road
- When may you overtake and pass a light rail vehicle or a streetcar on its left side?
- Who is required to wear a helmet when riding a bicycle in California?
- You are riding a bicycle after dark. From how far away must the white light of your front lamp be visible?
- A neighborhood electric vehicle (NEV) pulls out in front of you. What does the handbook say about which roads these vehicles may use?