Railroad Crossings and Mountain Driving - Complete Guide
Railroad crossings and mountain driving present unique hazards for commercial vehicles. Sections 2.15-2.16 of the CDL manual cover crossing types, required stopping procedures, safe speed selection for downgrades, and proper braking techniques—all frequently tested on the CDL exam.
Railroad Crossing Types
Passive Crossings
- No traffic control devices
- Decision to stop or proceed is entirely yours
- You must: recognize the crossing, search for trains, decide if safe to cross
Active Crossings
- Have traffic control devices to regulate traffic
- Include: flashing red lights, bells, and/or gates
- When lights flash or gates lower, you must stop
Warning Signs and Devices
Advance Warning Sign
- Round, black-on-yellow sign placed ahead of crossing
- Tells you to slow down, look, listen, and be prepared to stop
Pavement Markings
- X with "RR" painted on road
- No-passing marking on two-lane roads
- White stop line may be painted before tracks
Cross-buck Sign
- X-shaped sign at the crossing
- Requires you to yield right-of-way to trains
- Sign below indicates number of tracks if more than one
Flashing Red Lights
- Stop when lights flash—train is approaching
- Wait until lights stop and train has cleared
- Check all tracks before proceeding
Gates
- Stop when lights flash, before gate lowers
- Remain stopped until gates go up AND lights stop flashing
- Then proceed when safe
Stopping Requirements
Where to Stop
| Requirement | Distance |
|---|---|
| Minimum distance from nearest rail | 15 feet |
| Maximum distance from nearest rail | 50 feet |
When Full Stop is Required
- Cargo makes stop mandatory (hazmat, passengers)
- Required by state or federal law
- Any time you can't see clearly in both directions
Stopping Safely
- Check traffic behind you while stopping gradually
- Use pullout lane if available
- Turn on four-way emergency flashers
Crossing the Tracks
Time to Clear Tracks
| Track Type | Clearing Time |
|---|---|
| Single track | At least 14 seconds |
| Double track | More than 15 seconds |
Critical Rule: Never shift gears while crossing railroad tracks.
Before Crossing
- Be sure you can get all the way across before starting
- Never let traffic trap you on the tracks
- After one train clears, check for trains on other tracks
Vehicles That Can Get Stuck
Low-clearance vehicles at risk on raised crossings:
- Lowboy trailers
- Car carriers
- Moving vans
- Possum-belly livestock trailers
- Single-axle tractor with long trailer (landing gear set for tandem-axle)
If Stuck on Tracks
- Get out of vehicle and away from tracks
- Check signpost or signal housing for emergency number
- Call 911 or emergency number
- Give location with DOT number if posted
Railroad Crossing Safety Rules
| Do | Don't |
|---|---|
| Expect a train at every crossing | Race a train to crossing |
| Reduce speed to stop if needed | Rely solely on signals |
| Look both ways, even after train passes | Assume you'll hear the train |
| Check all tracks before crossing | Shift gears on tracks |
| Stop 15-50 feet from nearest rail | Get trapped on tracks by traffic |
Warning: It's extremely difficult to judge train speed and distance. Never try to beat a train.
Mountain Driving: The Basics
Gravity's Role
- Upgrades: Gravity slows you down—use lower gears to climb
- Downgrades: Gravity increases speed—must control with engine braking and proper technique
Factors for Selecting Safe Speed
Consider all five factors:
- Total weight of vehicle and cargo
- Length of the grade
- Steepness of the grade
- Road conditions
- Weather
Rule: If speed limit or "Maximum Safe Speed" is posted, never exceed it.
Engine Braking
The Primary Speed Control
Engine braking is the principal way to control speed on downgrades.
- Brakes are only a supplement to engine braking
- Engine braking is greatest when:
- Engine is near governed RPMs
- Transmission is in lower gears
Why Save Your Brakes
- Overuse causes brake fade (less stopping power)
- Continued hard braking can lead to complete brake failure
- Save brakes for when you truly need them
Selecting the Right Gear
The Critical Rule
Shift to low gear BEFORE starting down the grade.
Why Before?
- Once speed builds up, you cannot downshift
- You may not get into any gear
- You'll lose all engine braking effect
- Forcing automatic transmission at high speed damages it
Which Gear to Use
| Vehicle Type | Gear Selection |
|---|---|
| Older trucks | Same gear to go down as to climb up |
| Modern trucks | Lower gear going down than climbing up |
Modern trucks have less friction and air drag, so they need lower gears on downgrades.
Proper Braking Technique (Snub Braking)
The Snub Braking Method
This is the correct technique for long, steep downgrades:
Step 1: Apply brakes firmly to feel a definite slowdown
Step 2: Reduce speed to 5 mph below your safe speed
Step 3: Release brakes (application should last about 3 seconds)
Step 4: When speed returns to safe speed, repeat
Example
If safe speed is 40 mph:
- Don't apply brakes until speed reaches 40 mph
- Brake firmly to reduce speed to 35 mph
- Release brakes
- When speed returns to 40 mph, repeat
- Continue until end of downgrade
Key Point: This technique keeps brakes cool and effective.
Brake Fade and Failure
What Causes Brake Fade
- Using brakes too much instead of engine braking
- Excessive heat from continuous braking
- Brakes out of adjustment (some brakes do more work)
Warning Signs
- Need to press harder for same stopping power
- Brakes feel "spongy"
- Burning smell
Prevention
- Use engine braking as primary control
- Use snub braking technique
- Check brake adjustment frequently
- Select proper gear before descent
Escape Ramps
- Built on steep mountain downgrades
- Use loose, soft material to stop runaway vehicles
- May combine with upgrade
- Know locations on your route—signs indicate where they are
Escape ramps save lives, equipment, and cargo.
Frequently Asked Questions
Q: What is the difference between passive and active railroad crossings?
A: Passive crossings have no traffic control devices—you decide to stop or proceed. Active crossings have flashing lights, bells, and/or gates that tell you when to stop.
Q: How far from the tracks should you stop?
A: Stop no closer than 15 feet and no farther than 50 feet from the nearest rail.
Q: How long does it take a tractor-trailer to clear a double track?
A: More than 15 seconds. Single track takes at least 14 seconds.
Q: Should you shift gears while crossing railroad tracks?
A: No. Never shift gears while crossing tracks—you could stall on the tracks.
Q: What is the primary way to control speed on downgrades?
A: Engine braking. Brakes are only a supplement. Engine braking is most effective in lower gears near governed RPMs.
Q: When should you shift to a lower gear for a downgrade?
A: Before starting down the grade. Once speed builds up, you won't be able to downshift.
Q: What is the snub braking technique?
A: Apply brakes firmly to slow 5 mph below safe speed (about 3 seconds), release, let speed return to safe speed, then repeat. This keeps brakes cool.
Q: What gear should modern trucks use going downhill?
A: Usually a lower gear than needed to climb the same hill. Modern trucks have less friction and air drag.
Q: What causes brake fade?
A: Excessive heat from overusing brakes instead of engine braking. Brakes out of adjustment also contribute because some brakes work harder than others.
Q: What should you do if stuck on railroad tracks?
A: Get out and away from the vehicle. Call 911 with location and DOT crossing number if posted.
Next Steps
Memorize the key numbers:
- Stop 15-50 feet from tracks
- 14 seconds to clear single track
- 15+ seconds to clear double track
- Snub braking: 5 mph below safe speed, ~3 seconds
Ready to test your knowledge? Start practicing with our Railroad and Mountain Driving questions.