4.4 Drawbridges
Key Takeaways
- Stop at drawbridges that do not have a signal light or traffic control attendant; stop at least 50 feet before the draw of the bridge and look to make sure the draw is completely closed before crossing.
- You do not need to stop, but must slow down and make sure it is safe, when a traffic light shows green or when an attendant or traffic officer controls traffic whenever the bridge opens.
- A railroad-highway stop is between 15 and 50 feet from the tracks; a drawbridge stop is at least 50 feet before the draw, and only when there is no signal or attendant.
- 49 CFR 383.117(a)(4) requires passenger-endorsement applicants to know proper procedures at both railroad-highway grade crossings and drawbridges.
4.4 Drawbridges
Quick answer: If the drawbridge has no signal light and no traffic control attendant, stop at least 50 feet before the draw and make sure the draw is completely closed before you cross. If a traffic light shows green, or an attendant or traffic officer controls traffic whenever the bridge opens, you do not need to stop, but you must slow down and make sure it is safe. That is not the railroad 15-to-50-foot rule.
49 CFR 383.117(a)(4) tests railroad-highway grade crossings and drawbridges as required passenger knowledge. CDL Manual 4.3.6 is the drawbridge procedure. Drivers who memorize only the railroad numbers fail this item by stopping 15 feet from a draw, or by treating every drawbridge like a gated rail crossing that always demands a full stop.
When you must stop
Stop at drawbridges that do not have a signal light or traffic control attendant. That is a two-part trigger. If either a signal light or an attendant/officer is controlling the opening, you are in the exception discussed below. If neither is present, you stop.
Stop at least 50 feet before the draw of the bridge. The measuring point is the draw — the movable span that lifts, swings, or retracts — not a random point on the approach, and not the first expansion joint you dislike. "At least 50 feet" is a minimum. You may stop farther back if that is what you need to see the span and to keep the bus off a rise you cannot see over. You may not creep to 15 feet and call it close enough because that number felt familiar from railroad crossings.
Look to make sure the draw is completely closed before crossing. Partially closed is still open. A span that is coming down is not closed. A leaf that looks low from a distance can still have a gap at the lock. You need a view that answers the question, not a hope that the last boat has cleared.
Why the stop exists
A drawbridge without a signal or attendant gives you no mechanical promise that the roadway is a roadway. The span can be up for a vessel, stuck off the locks, or opening as you approach. A passenger bus that reaches the gap at highway speed has no recovery. The 50-foot stop is the last controlled place to look before the coach is committed to steel that may not be there.
Do this in order:
- Identify that there is no signal light and no traffic control attendant.
- Stop at least 50 feet before the draw.
- Look until you can say the draw is completely closed.
- Only then cross, still ready to stop if something in the span view changes.
When you do not need to stop
You do not need to stop, but must slow down and make sure it is safe, when:
- There is a traffic light showing green; or
- The bridge has an attendant or traffic officer who controls traffic whenever the bridge opens.
Both exceptions assume someone or something is managing the opening. A green light is a go indication only after you have slowed enough to confirm the span is actually a closed roadway. An attendant or officer who is there whenever the bridge opens is not the same as a vacant booth. If the person is supposed to control traffic during openings and is doing that job, you may proceed without the 50-foot full stop — still slowing and verifying it is safe.
A dark signal, a flashing red, or an empty control house puts you back in the must-stop case. Do not invent a third exception for "I can see the river and it looks fine from 200 feet at 45 mph."
| Drawbridge condition | Full stop at least 50 ft before the draw? | What you still do |
|---|---|---|
| No signal light and no traffic control attendant | Yes | Confirm the draw is completely closed, then cross |
| Traffic light showing green | No | Slow down and make sure it is safe |
| Attendant or traffic officer who controls traffic whenever the bridge opens | No | Slow down and make sure it is safe |
| Signal dark / attendant absent | Yes — treat as uncontrolled | Stop at least 50 feet before the draw |
Contrast with railroad-highway crossings
P applicants mix these two 383.117(a)(4) procedures because both involve stopping a bus short of a gap in the roadway. The numbers and the triggers are different.
| Rule | Railroad-highway grade crossing (4.3.5 / 392.10) | Drawbridge (4.3.6) |
|---|---|---|
| When a full stop is required | Default for every bus transporting passengers, except the listed exceptions | Only when there is no signal light and no traffic control attendant |
| Distance | Between 15 and 50 feet before the tracks | At least 50 feet before the draw |
| Far/near edge | Not closer than 15 ft; not farther than 50 ft | Minimum 50 ft; farther is allowed |
| Extra check | Look and listen for trains; second train on other tracks; no shift on the rails | Look to make sure the draw is completely closed |
| No-stop exceptions | Streetcar; officer/flagman; green signal; exempt or abandoned (slow and check) | Green traffic light; attendant/officer who controls openings (slow and verify safe) |
Memorize the contrast as: railroad is a 15-to-50-foot box at almost every passenger-bus crossing; drawbridge is a 50-foot-or-more stop only when the span is uncontrolled. If a stem gives you 15 feet at a drawbridge, it is recycling the railroad number. If a stem makes you stop at a drawbridge that has a green light and an attendant, it is recycling the railroad "always stop" habit.
Exam traps
- The drawbridge measuring point is the draw, not the first lamp post on the approach.
- At least 50 feet is not "about 15 to 50 feet." There is no 15-foot minimum on a drawbridge stop.
- A green light removes the full stop, not the duty to slow and confirm the span is closed and the way is safe.
- 383.117(a)(4) will test both procedures on the same endorsement. Knowing only railroad numbers is not enough to pass the drawbridge item.
When must you stop at a drawbridge, and how far from the draw?
When do you not need to stop at a drawbridge, provided you slow down and make sure it is safe?
How does the passenger-manual drawbridge stop differ from the railroad-highway grade-crossing stop, and why does the P test ask both?