5.1 Cockpit Drill (DSSSM), Seating Ergonomics, and Primary Vehicle Controls

Cockpit Drill (DSSSM), Seating Ergonomics, and Primary Vehicle Controls

Safe motor vehicle operation begins long before the wheels turn on public roads. Establishing an uncompromising pre-drive routine inside the vehicle cabin—commonly termed the cockpit drill—ensures mechanical preparedness, optimal ergonomic control, and legal compliance. Sri Lankan driving instructors teach a cockpit routine so that learners never drive with poor visibility, the wrong pedal reach or unsecured doors. Section 152(1) of the Motor Traffic Act makes it an offence to drive where you do not have full control of the vehicle or a full, unobstructed view of the road.

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1. The Standardized Cockpit Drill: The DSSSM Routine

The universally recognized mnemonic for the pre-drive vehicle check is DSSSM: Doors, Seat, Steering, Seatbelt, and Mirrors. This systematic routine must be completed in exact chronological sequence every time a driver enters a vehicle.

Step 1: Doors (D)

Before operating any controls, ensure all passenger doors, the boot lid, and the engine bonnet are securely latched. Modern vehicles display a red or amber door-ajar warning symbol on the instrument panel if any door latch remains unseated. When carrying children, engage the child safety locks on the rear doors so that they cannot be opened from inside while the vehicle is moving. When exiting a parked vehicle along a public carriageway, drivers should practice the "Dutch Reach"—using the far hand (left hand in a right-hand drive vehicle) to open the door, which naturally pivots the driver's torso to spot approaching cyclists or motorcyclists.

Step 2: Seat and Seating Position (S)

Correct seating ergonomics provide the mechanical foundation for precise vehicle control and rapid reaction times:

• Pedal Distance: Slide the seat forward or backward so that when the clutch pedal (in a manual vehicle) or the brake pedal (in an automatic vehicle) is depressed completely to the floorboard, the knee remains slightly bent at approximately 120 degrees. Never adjust the seat so far back that the leg must lock completely straight to reach full depression, as locked joints cannot exert maximum emergency braking pressure and suffer severe catastrophic fractures during frontal collisions.
• Seat Height: Raise or lower the seat cushion so that the driver's eyes are positioned roughly halfway up the windscreen, ensuring an unobstructed forward horizon and complete visibility of all dashboard warning lights and the speedometer.
• Backrest Angle: Adjust the backrest to a nearly upright angle (approximately 100 to 110 degrees). Test reach by extending both arms straight forward: the driver's wrists must rest comfortably on top of the steering wheel rim without stretching the shoulder blades away from the backrest.
• Head Restraint: Adjust the head restraint so that the rigid center cushion aligns horizontally with eye level (or the top of the ears) and sits within 2 to 5 centimetres of the back of the head. In rear-end collisions, a properly positioned head restraint catches the skull instantly, preventing severe hyperextension whiplash injuries.

Step 3: Steering Wheel (S)

Adjust the steering column's tilt and telescopic reach so that the wheel does not obscure the instrument cluster. The driver must maintain an unobstructed view of the speedometer, fuel gauge, engine temperature gauge, and warning indicators. The driver's chest should remain at least 25 to 30 centimetres (10 to 12 inches) away from the center hub to allow the supplemental restraint system (SRS) airbag to deploy safely without causing blunt force trauma.

Step 4: Seatbelt (S)

Section 157A of the Motor Traffic Act and the Motor Traffic (Seat Belts) Regulations No. 3 of 2011 require occupants of the prescribed seats to wear an approved seat belt, and not wearing one is a spot-fine offence. On expressways the RDA requires every occupant, including rear-seat passengers, to wear a belt. Make everyone in the car buckle up before moving off. Correct positioning of a three-point inertia-reel belt:

• The diagonal shoulder strap must pass snugly across the center of the clavicle (collarbone) and breastbone. It must never rub against the neck, cut into the throat, or be tucked underneath the armpit.
• The lap strap must rest flat and low across the pelvic hip bones. It must never cross the soft abdomen, where collision forces can cause massive internal organ ruptures.
• Pull upward on the diagonal belt to eliminate slack and verify that the retractor mechanism locks when tugged sharply.

Step 5: Mirrors (M)

Mirrors must be adjusted only after the seating position has been finalized:

• Interior Rearview Mirror: Frame the rectangular mirror evenly around the entire rear window glass so that the driver can see the full road behind without moving their head, using only rapid eye movements.
• Exterior Side Mirrors: Adjust each side mirror so that the horizon sits horizontally across the middle of the glass. The vehicle's own rear flank should occupy only a narrow sliver—approximately 10% to 15%—along the inner edge of the mirror. This tiny sliver provides an essential spatial reference point while dedicating 85% to 90% of the reflective surface to adjacent traffic lanes, drastically reducing blind spots.

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2. Steering Technique and Hand Placement

Modern automotive steering systems require disciplined hand positioning to maintain directional stability, execute evasive maneuvers, and prevent injuries from airbag deployment.

Hand Positions: 10-and-2 vs. 9-and-3

Older driving lessons taught the ten-to-two (10-and-2) clock position. However, with the universal introduction of driver steering-wheel airbags, modern defensive driving standards equally approve and encourage the quarter-to-three (9-and-3) grip:

• Airbag Protection: In the event of a frontal crash, the central airbag module deploys at speeds exceeding 250 to 300 km/h. At 9-and-3, the driver's arms are propelled outward laterally rather than directly into the driver's face, preventing fractured forearms and facial lacerations.
• Thumbs Placed Along Rim: Never hook your thumbs inside the inner spokes of the steering wheel. If a front wheel strikes a deep pothole, kerb, or road debris, the steering wheel can violently kick back, causing severe sprains or fractures to hooked thumbs.

The Pull-Push (Shuffle) Steering Method

Driving schools teach the pull-push steering method (also known as shuffle steering) for curves and turns, which keeps both hands on the wheel as section 152(4) of the Act requires:

1. Both hands begin at 9-and-3 or 10-and-2.
2. To turn left, the left hand slides up toward the 12 o'clock position and pulls the rim downward toward 6 o'clock, while the right hand slides down the right side of the rim simultaneously.
3. The hands pass the wheel between each other at the bottom and top, never crossing over the center line.
4. Why Crossing Arms is Prohibited: Crossing arms over the steering hub ("hand-over-hand" through tight bends) leaves the forearms directly over the airbag compartment. If an impact occurs while turning with crossed arms, the deploying airbag will blast the driver's hands into their head with explosive force.

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3. Primary Foot Controls: Manual vs. Automatic Transmissions

Light motor vehicles (Class B / Dual Purpose) in Sri Lanka are equipped with either manual or automatic transmissions. The pedal arrangements, functions, and operational rules differ fundamentally between the two drivetrain configurations.

  MANUAL PEDAL LAYOUT (RHD)              AUTOMATIC PEDAL LAYOUT (RHD)
  
  [ CLUTCH ]  [ BRAKE ]  [ ACCEL ]       [ FOOTREST ]   [ BRAKE ]  [ ACCEL ]
      |           \         /                 |             \         /
      |            \       /                  |              \       /
  [LEFT FOOT]     [RIGHT FOOT]           [LEFT FOOT]       [RIGHT FOOT]
  (Depress fully  (Alternates between    (Firmly parked    (Alternates between
   for shifts)     Brake & Throttle)      on footrest)      Brake & Throttle)

Manual Transmission Foot Controls (C-B-A)

1. Clutch Pedal (Extreme Left): Operated exclusively by the left foot. The clutch physically connects and disconnects engine torque from the transmission gearbox. When the pedal is depressed fully to the floorboard, power transfer ceases, allowing the driver to select gears or bring the car to a halt without stalling the engine.
   • The Biting Point (Friction Point): As the clutch pedal is slowly released, the friction plates make initial contact and the vehicle begins to creep forward. Drivers must pause momentarily at this biting point while applying gentle throttle, then release the pedal smoothly.
   • Prohibited Habits: Clutch riding (resting the left foot continuously on the clutch pedal while driving) causes rapid wear and overheating of the release bearing and friction plate. Coasting (travelling with the clutch held down or the gear in neutral) removes engine braking, causing excessive brake fade on hills and reducing vehicle stability.
   • Where Your Feet Belong: The DMT sample paper asks where each foot should be at different moments in a manual car. When cruising in gear, rest the left foot on the floor or footrest beside the clutch (not on the pedal) and use the right foot for the accelerator. When moving off, the left foot releases the clutch while the right foot applies gentle throttle. In slow, stop-start traffic, keep the right foot ready to brake.
2. Footbrake Pedal (Center): Operated exclusively by the right foot. Pressing the footbrake actuates hydraulic disc and drum brakes on all four wheels, activating rear red brake lights to warn following motorists. Braking must be smooth, progressive, and completed before entering a corner.
3. Accelerator Pedal (Extreme Right): Operated exclusively by the right foot. Regulates the fuel-air throttle mixture and engine revolutions per minute (RPM). Requires light, progressive toe pressure.

Automatic Transmission Foot Controls (B-A)

Automatic vehicles eliminate the clutch pedal, leaving only the broad Footbrake pedal on the left and the Accelerator pedal on the right.

• The Dead Pedal (Left Foot Rest): The left foot must remain firmly planted on the angled dead pedal (footrest) on the left side of the footwell at all times.
• Danger of Two-Footed Driving: Never attempt to operate the brake with the left foot while operating the throttle with the right foot. In an emergency, natural panic reflexes cause drivers to depress both feet simultaneously, overriding braking force, causing transmission damage, and confusing following drivers by keeping brake lights illuminated while accelerating.

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4. Secondary Controls and Dashboard Operation

Secondary vehicle controls manage illumination, communication, road visibility, and parking security. Mastering their tactile locations prevents drivers from glancing away from the roadway while driving.

Handbrake / Parking Brake

The mechanical handbrake (or electronic parking brake / EPB) acts mechanically on the rear wheels to hold the vehicle stationary when parked or paused on steep inclines:

• Applying the Mechanical Handbrake: Press the ratchet release button at the tip of the lever while pulling upward smoothly to the top notch, then release the button. This prevents unnecessary wear on the ratchet teeth and pawl.
• Releasing: Pull upward slightly, depress the button fully, and push the lever down completely until the instrument cluster brake warning light turns off.

Automatic Gear Selector Positions (P-R-N-D-L)

Modern automatic shifters feature standardized gate positions:

• P (Park): Inserts a mechanical locking pawl into the transmission output shaft. Must be selected only when the vehicle is completely stationary. Always set the handbrake before shifting into Park on inclines to prevent shearing the parking pawl.
• R (Reverse): Engages backward motion, illuminating white reverse lights and activating reversing cameras or acoustic chimes.
• N (Neutral): Disengages all gears. Wheels rotate freely. Used when restarting a stalled engine or during temporary stationary idling with the handbrake applied.
• D (Drive): Normal forward driving. The transmission shifts automatically through forward gears (1st through 6th, 7th, or 8th gear, or CVT continuous ratios).
• L / 2 / 1 (Low Range): Locks transmission into lower gears. Essential in Sri Lanka's steep mountainous terrain (such as the Central Highlands around Kandy, Nuwara Eliya, and Ella) to utilize engine braking on steep descents and prevent catastrophic brake overheating and failure.

Auxiliary Switches and Levers

• Direction Indicators & Light Stalks: In standard Japanese RHD light vehicles, the turn indicator stalk is mounted on the right side of the steering column, while the windscreen wiper stalk is on the left side. In European models, this layout is frequently reversed. Candidates must verify their control stalk locations prior to driving.
• Hazard Warning Flashers: Flashes all four amber indicators together. The DMT sample paper's answer is that hazard lamps warn others that your vehicle has stopped because of a breakdown or emergency in a place where it would not normally stop. They do not signal "I am going straight on", do not give you priority, and do not make illegal parking legal. Section 153(2) forbids any other flashing lights on or in the vehicle.
• Horn Usage: Section 155(2) of the Motor Traffic Act allows the horn only as a warning to avoid an accident, or to show you intend to overtake. Multi-tone or harsh horns are banned for ordinary vehicles. Where the PHS-09 No Horning sign is posted (near hospitals, schools and court houses), the horn must not be used.