Module Five Navigating Roadways 1 Module Five – Part 2 Navigating Roadways Topic 1 Intersections Pages 31-32 Topic 2 Curves – Page 33 Topic 3 Hills and Mountains Passing and Lane Changes – Teacher handout 2 What do you see at this intersection? 3 One out of three fatal crashes occurs at intersections due to: Drivers fail to search and identify a safe path of travel when approaching an intersection Drivers don’t identify or understand the risks Drivers fail to develop good driving habits to effectively manage the risks 4 Crossroad – Four-way intersection T Intersection - one road ends where the other road crosses Y Intersection – you must bear either right or left ahead 5 Roundabout – a circular intersection in which entering traffic must yield right of way Railroad Crossing – road intersects with a railroad crossing 6 Two-way road crossing two-way road One-way road crossing one-way road One-way road crossing two-way road One-way road merges with multi-lane road 7 If possible, begin searching 20-30 seconds ahead of the intersection Using an orderly visual search pattern Identify the type of intersection Identify open, closed and changing zones Identify the best lane and lane position Determine if the intersection is controlled or uncontrolled 8 Intersection flow is regulated by STOP signs, YIELD signs or traffic SIGNALS 9 There are No Signs or Traffic Lights Traffic Light is Malfunctioning The first vehicle that arrives at the intersection may proceed first if the other yields right of way If two vehicles arrive at the same time, the driver on the left must yield to the driver on the right 10 When you can see the intersection, begin SEARCHING for the Type of intersection Intersection controls Risks or problems in your intended path of travel Also monitor the areas to the rear 11 During your Search you identified potential risks, and you must now Evaluate your options on how to handle: Traffic Controls Stop sign, yield sign, traffic light No traffic controls Open, closed or changing path of travel Cross traffic 12 You have Searched, and Evaluated and determined the best course of action. You must now EXECUTE in Time Position vehicle in proper lane Obey traffic controls and prepare to yield if necessary Search and monitor space as you carefully proceed through the intersection 13 Time Needed to Execute If proceeding straight across a 30-feet wide, 2-lane roadway from a stop you need a 4-second gap If turning right and blending into the traffic flow you need a 6second gap If turning left and blending into the flow of traffic, you need an 8- second gap 14 Vehicles traveling 30 mph, are traveling at approximately 45 feet per second To safely cross the intersection, the Vehicles from the right must be at least 270 feet away To safely turn right and blend into traffic, the Vehicles approaching from the left must be 360 feet away To safely turn left and blend into traffic, the Vehicles approaching from the right must be 495 feet away 15 Select the best lane at least a block ahead Center lane(s) – safest when traveling straight through Right lane is used when turning right - cross traffic, turning right on red will enter this lane Left lane is used to turn left - yield to oncoming traffic 16 Vehicles turning right on red Permitted throughout the United States unless you see these signs Why? Right turn on red law saves gas! The law requires drivers to STOP, (wheels motionless) before making the right on red- not a “rolling” stop! 17 Look for clues: Driver is looking to the left or right Vehicle positioned on the left side of the lane Front wheels are turning left or right Pedestrian standing at curb 18 Right-of-way rules not followed Failure to signal Failure to search intersections Failure to stop on red before turning right Turning too wide and crossing into adjacent lane 19 Shared lanes help keep traffic moving by giving drivers turning left a designated shared lane in the center of the roadway 20 Use shared lanes to start and complete left turns 21 Crossing traffic entering a shared lane from a driveway Move all the way into the lane to avoid blocking through traffic lane Stop in the shared lane and wait to merge safely with traffic Is the black truck allowed to stop in the shared lane and wait for traffic to the right to clear? 22 Look for other drivers using the shared lane You can only travel 150 feet in a shared lane Collisions do occur in shared lanes! 23 A circular intersection controlled by yield signs Entries and exits into and out of the circle can be at multiple locations By yielding at the entry, rather than stopping and waiting for a green light or stopping at a stop sign, significantly reduces delays 24 Fewer points of conflict The data shows a 90% reduction in fatal crashes 75% reduction in injury crashes Reduces delays and keeps traffic moving Reduction in pollution and fuel use 25 Module Five Navigating Roadways 26 Curvy roads present a high risk There are many line-of-sight and/or path-of-travel restrictions (trees, hills, etc.) Blind Curve Only a portion of the corner is visible; the rest is hidden S-Curve A curve in one direction with a second curve in the opposite direction S Curve Crowned Roadways Most roadways are higher in the middle and slope to the outside for better drainage If a road curves to the left on a crowned roadway, what happens to the weight of the vehicle? Banked Curve The outside of the curve is higher than the inside How does a banked curve help vehicles stay on the road when navigating the curve? Banked Curve Uphill: acceleration is needed to maintain speed Downhill: vehicles will naturally pick up speed Why do vehicles “slow down” going uphill and “speed up” coming downhill? Sharp Curve Curve to right followed by curve to left Winding Road Road curves right – vehicle’s weight shifts left Maximum SAFE speed is 25 mph Entrance Apex Approximately the middle of the curve Exit Friction The resistance to motion between materials moving over one another Traction Friction between tires and the road surface Keeps vehicle on the road and allows vehicle to respond to acceleration, braking and steering Traction is reduced by speed centrifugal force road conditions worn tires Vehicle weight shifts When traction is lost, the vehicle does not respond to driver input Inertia An object moving in a straight line will continue in a straight line unless another force acts on it Inertia must be overcome to round the curve Traction is needed to overcome inertia If a vehicle loses traction in a curve, the vehicle will continue straight Inertia and traction are affected by Road surface, condition of tires, speed, sharpness of curve Inertia increases with increased speed and sharpness of the curve Traction decreases with increased speed, reduction in tire’s contact with road surface and road surface conditions Vehicle Weight Transfer The weight of a vehicle rounding a curve shifts to the opposite direction of the curve Rounding a curve to the right will result in the vehicle’s weight transferring left The right tires may lose contact with the road resulting in less traction Photo courtesy of AAA Foundation Rounding a curve with too much speed can result in the vehicle turning over Adding weight to the top of a vehicle also increases the tendency to turn over as the center of gravity has been raised Speed control and smooth, controlled steering are needed to maintain control Vehicle performance in a curve depends upon Weight of the vehicle Center of gravity of the vehicle Speed Pavement conditions Tire condition Driver input What is the best method of steering through this curve? Why? Search the road ahead • • • • • Uphill/downhill? Blind curve? Crowned or banked? Sharpness of curve? Road surface conditions? What can you determine as you search the curve ahead? After Searching Evaluate your options Lane position Visibility Space management Speed control Controlled braking before apex Accelerate out of the curve Steering Push-Pull Line of sight Look through the curve Path of travel Execute in Time When approaching a Curve to the Left It is generally best to approach the curve in Lane Position 3, as far away as possible from oncoming traffic This position also provides the best targeting point for your line of sight Diagram on workbook page 33 #1 Begin in Lane Position 3 When approaching a Curve to the RIGHT An outside road position on entry to a right curve (Lane Position 2) allows for a longer braking distance on entry and a better chance of establishing a sightline to the apex and exit of the curve Diagram page 33 #2 Begin in Lane Position 2 Hills and Mountains Applying SEEiT Search ahead for advisory speed signs, oncoming traffic, road conditions for traction control, and slow moving vehicles Evaluate if the hill has curves and determine the type of curve for decision-making about speed and lane positions Driving Uphill—Speed Control Extra power may be needed to maintain uphill speed Slower moving vehicles should travel in the right-hand lane Photo courtesy of AAA Foundation What is gravity? How does it affect a vehicle on hills or mountains? Descending Hills & Mountains Gravity will make the vehicle go faster Downshift and use the transmission to reduce speed and help keep brakes from overheating and overheating What are the clues in this scene that describe the roadway conditions? Descending Heavier vehicles will pick up more speed downhill because of gravity Check the rear zone for vehicles that may be having trouble controlling speed Turn off the cruise control What should the pickup truck driver remember when passing the tanker truck? Cresting the Hill The LOS at a hill crest is very limited Be prepared for: Stopped vehicles Slow moving vehicles Oncoming vehicle in your lane Be prepared adjust speed or position to avoid a hazard What potential hazards could exist on the other side of the hill crest? Carry Out Your Decision Adjust speed and/or position if needed What would you do if an approaching vehicle crossed the center of the road? Runaway Ramps Runaway ramps are designed for large trucks that lose braking control on steep hills These sections have deep gravel, sand barrels and other materials to help slow down the runaway vehicle Pull off the road if you see a runaway truck behind you Starting on Hills—Automatic Transmission Some steep hills require using the accelerator and brake together to keep the vehicle from rolling backward Maintain brake pressure until ready to move Use the right foot to accelerate and simultaneously slowly release the brake Refer to notes handout **Use SMOG (signal, mirrors, over shoulder, go) 1. Check traffic ahead, to the sides, and behind 2. Signal 3. Check your mirrors – rear view and side view 4. Make a head check 5. Accelerate smoothly 6. Change lanes smoothly 7. Cancel signal 8. Adjust speed and/or vehicle position to create space all around your vehicle 1. Check traffic ahead, to the sides, and behind Signal 2. Make a head check 3. Accelerate smoothly 4. Change lanes smoothly 5. Cancel signal 6. Pass and signal to return 7. Check mirrors 8. When both sets of headlights of the vehicle being passed are visible, return to the lane 9. Cancel signal 10. Adjust speed and/or vehicle position to create space all around your vehicle Monitor passing vehicle’s position Move to lane position 3 to increase space cushion Do not increase speed—decelerate if necessary Once passed, create space ahead and behind REGULAR SIZED MOTOR VEHICLE _____ FOOTBALL FIELDS At 40 Mph – You would need 5 FOOTBALL FIELDS TRACTOR TRAILER _____ FOOTBALL FIELDS At 40 Mph – You would need 7.5 FOOTBALL FIELDS Hills Railroad crossings Solid yellow lines Curves Intersections Headlights increase visibility of a vehicle, passing vehicles, and oncoming vehicles.
