Driving Environments

Different Driving Environments

  • The space around your car changes depending on the driving environment.

  • Time and space are crucial considerations.

Time and Space

  • Concepts like speed and distance are interconnected.

  • Blinking Example:

    • Blinking takes approximately 1/3 of a second.

    • At 30 mph (44 feet per second), a car travels about 15 feet (one car length) during a blink.

      • \frac{1}{3} \text{ second} * 44 \frac{\text{feet}}{\text{second}} = 14.67 \text{ feet}

    • At 65 mph, a car travels about 30 feet (a couple of car lengths) during a blink.

Importance of Attention

  • Looking away from the road for a second (e.g., adjusting controls, talking to a passenger) significantly increases the distance traveled without visual attention.

  • The Smith System emphasizes keeping eyes moving to avoid focusing on one thing for too long.

Reaction Time

  • Perception Time: Time for the brain to recognize a situation.

  • Reaction Time: Time for the brain to send signals and the body to respond; approximately one full second.

    • In one second, a car travels about 44 feet on side roads and about 95 feet on the highway.

Reaction Times Vary

  • Reaction times vary among individuals, but relying solely on reaction time is risky.

  • Maintaining a safe following distance is more reliable.

Stopping Distance

  • The stopping distance depends on two factors, the thinking distance, and the braking distance.

  • Thinking Distance: The distance the car travels during the driver's reaction time.

    • Factors Increasing Thinking Distance:

      • Tiredness

      • Alcohol/Drugs

      • Distractions (loud music)

      • Higher Speed

      • Older Age

  • Braking Distance: The distance the car travels while braking.

    • Influenced by:

      • Speed

      • Weather conditions (rain, snow, puddles)

      • Brake condition

      • Tire grip

Velocity Time Graph

  • During the thinking distance, the velocity remains constant. However, during the braking distance, the car gradually reduces its velocity.

  • The area underneath a velocity time graph gives us the distance traveled by the car.

  • Stopping distance = Thinking distance + Braking distance

  • Time and space are related; higher speeds require longer stopping distances.

Risk and Speed

  • Crashes at high speeds are often due to drivers maintaining the same following distance as at lower speeds, despite the increased stopping distance.

  • Excessive speed increases stopping distance proportionally.

Factors Affecting Braking Distance

  • Tires: Critical for connecting to the road; affects starting, stopping, and turning.

  • Road Conditions: Leaves, pavement smoothness (e.g., parking garages).

  • Brake Quality: Essential for effective stopping.

Average Stopping Distances

  • Includes perception time and physical reaction time (thinking distance) plus braking distance.

  • At highway speeds (60-70 mph), stopping distance is approximately a football field length (315 feet).

Following Distance (Space Cushion)

  • Measured in seconds, not car lengths.

  • The three-second rule: Maintain at least three seconds of following distance under normal conditions.

  • How to measure it:

    • Choose a fixed object on the side of the road and count the seconds after the vehicle in front of you passes the same object using "one thousand and one… until three".

  • Increase following distance in adverse conditions:

    • Rain: at least six seconds.

    • Snow, fog, or icy conditions: nine to twelve seconds.

  • Legal responsibility: Hitting someone from behind is usually considered your fault.

  • Practice as a passenger: Judge the distance between you and the car in the front.

Look-Ahead Distance

  • Focus on how far down the road you should be looking.

  • Don't focus solely on the brake lights of the car in front; look ahead three to four cars.

  • Anticipate traffic slowdowns and adjust speed gradually to avoid sudden stops.

  • Look for pedestrians and anticipate their actions (e.g., crossing the road).

  • Try to look twelve, fourteen, sixteen seconds ahead what's happening in the future, not what's happening right in front of you.

Urban Driving

City Driving Environment

  • Characterized by more: cars, pedestrians, signs, construction, parked cars, obstacles and building block vision.

  • Apply the same driving skills as in other environments, even if it seems overwhelming.

  • Maintain three-second following distance and look far down the road.

Vision Zero

  • Initiatives to end traffic deaths and severe injuries on city streets.

  • Focus on improving safety for all road users.

  • Drivers play a critical role and must be proactive.

City Driving Facts

  • Most collisions occur in daylight, in good weather, and while going straight.

  • Slow down, even at 25 mph; it takes 85 feet (almost seven car lengths) to stop.

  • Slowing down reduces the severity of collisions.

    • 20 mph: 5% chance of death if a pedestrian is hit.

    • 40 mph: 85% chance of death if a pedestrian is hit.

Street Redesign

  • Many cities redesign streets to enhance safety for pedestrians and cyclists.

Street Design Elements

  • All intersections are crosswalks, marked or unmarked.

  • Marked crosswalks are indicated with thick lines to enhance visibility.

  • Raised crosswalks: These act as speed bumps and warn drivers to expect people crossing.

  • Limit lines, yield lines, sharks teeth, and pedestrian yield signs show drivers where people will cross and where to stop to keep space clear.

  • Bulb outs (sidewalk extensions) make pedestrians more visible and help drivers slow down during right turns.

  • Leading interval signals give pedestrians a head start before traffic moves.

  • Pedestrian scrambles halt traffic in all directions to allow pedestrians to cross in any direction, including diagonally.

  • Rapid flashing beacons alert drivers to pedestrians crossing.

  • Pedestrian crossing lights turn flashing yellow and then solid yellow before turning solid red.

  • Traffic circles slow traffic and reduce conflicts; stop before entering and yield to traffic within the circle.

  • Cheros indicate shared lanes for bikes and vehicles.

  • Bike lanes are exclusive for cyclists and can be unprotected, buffered, or protected.

  • Dashed bike lanes indicate mixing zones for turns.

  • Elevated bike lanes provide a separate space for cyclists.

  • Bike box areas at intersections provide space for cyclists at the front of the line.

  • Advanced limit lines, yield lines show drivers where people will cross and where to stop to keep space clear.

  • Bicycle traffic signals offer exclusive phases for bicycle traffic.

Driving Near People

  • Adjust mirrors to minimize blind spots.

  • Be ready to stop or maneuver quickly due to unexpected actions from pedestrian.

  • Scan from building to building, not just curb to curb to search for pedestrians.

  • Watch sidewalks, alleys, behind parked vehicles, and people who may enter your path.

  • Be patient when turning and always check crosswalks.

  • Expect the unexpected

Pedestrians

  • All intersections are legal crosswalks.

  • Pedestrians have the right-of-way.

  • Children, seniors, and people with disabilities are particularly vulnerable.

  • Give buses and streetcars extra space due to passengers embarking and disembarking.

  • Don't block the box (intersections or crosswalks).

Bicycles

  • Most city streets are legal for bicycles.

  • Keep a safe distance behind cyclists.

  • Give at least three feet of space when passing.

  • Cyclists may avoid bike lanes due to hazards or turns.

  • Expect cyclists to filter to the front of traffic or pass on the right.

  • Tap the horn to make your presence known but avoid unnecessary honking.

  • Be careful when taking right turns.

Parking/Loading

  • Check for people when parking or loading.

  • Open the driver's side door with your right hand to turn and look for cyclists.

  • Remind passengers to check before opening doors.

  • Use loading zones; avoid stopping in bike or transit lanes.

Weather

  • Slow down and drive carefully in adverse conditions (rain, snow, fog, low lighting).

  • Roadways may be slippery.

Responsibility

  • Drivers are responsible for safety on city streets.

  • Traffic deaths and severe injuries are avoidable.

  • Aim for Vision Zero.

Boston Driving

  • Boston drivers known for being aggressive.

  • Lower speed limits to 25 mph (or 20 mph in zones) to reduce crashes and improve safety.

  • Slowing down and increasing space smooths traffic flow.

Start and Stop Traffic

  • Leave a little extra space and watch far down the road.

  • Can kind of see traffic flow by looking through the rear window and windshield.

Negotiating with Pedestrians

  • Be Polite and Patient

  • If there is a heavy flow of pedestrians, slowly pull slightly into the intersection to make a space for them to walk around the car so that you can proceed with the turn.

Rural Driving

Rural Roads

  • Dirt or gravel roads decrease traction.

  • Fewer road markings.

  • Higher default speed limits.

  • Roads may drop off into gullies.

  • Possible large farm equipment on road.

  • Potential for farm animals crossing roads.

  • Leave more space, slow down, keep your eyes moving, and use good vision. They still work, even though it's a a much different environment than a city.

Gravel Roads

  • Crash rates are more than twice that of state highways.

  • Slow down due to obstacles such as mailboxes and paper delivery boxes.

  • Orange triangle on vehicles means slower speeds and the drivers need to be cautious.

  • They will still be no passing zones.

Driving on Hills

  • Slowing down and not noticing: On a slight hill, people might slow down a couple of miles an hour or less and it may catch up to the other cars on the road.

  • A lot of people think traffic jams start because somebody gets in an accident or something like that. It's usually just somebody slows down a little bit more, you know, in a place where you wouldn't expect them to, and then that causes the people following too close to hind to actually hit their brakes. Once somebody hits their brakes, everybody starts hitting their brakes.

  • People Slow Down and Do Not Notice It: This is because they may be going up a slight hill and they may slow down a couple of miles just a little bit more than they think.

  • At the Top Of A Hill: It will be more difficult to see. You will not see as far ahead. Look ahead distance is reduced.

  • DownHill is a little bit of the opposite.

  • If you're on the brakes all the time or riding the brakes, then it can affect how hot they get. Then the material on the pads gets so hot that they won't grip anymore, and then you won't have any braking power on those brakes.

Uphill Travel

  • Drivers may slow down without realizing it.

  • Traffic jams can start at the crest of a hill due to reduced visibility.

  • Leave sufficient space to avoid sudden braking.

Downhill Travel

  • Drivers may accelerate too much downhill.

  • Avoid continuous braking on long, steep downhill sections to prevent brake failure.

  • Instead, brake hard for short intervals and then coast.

  • Use engine braking by shifting to a lower gear in automatic transmissions.

Parking Brake

  • The driver can use a parking brake if their brakes are failing because they are going down a hill.

Mountain Driving Hazards

  • Sudden sharp curves.

  • Dangerous drop offs.

  • Falling rocks.

  • High winds.

Mountain Driving Safety

  • Before traveling be sure to do the following:

    • Check tire pressure.

    • Double check brakes.

    • Test parking brake.

Slowing Moving Vehicle

  • School buses have different rules for slowing down. You can pass a slow moving vehicle across the double yellow line if nobody's coming the other way, and it is safe and you're not near an intersection or a bridge. If somebody's just driving too slow, you can't pass them unless there's a passing zone.

Road Test Info

  • Get everything done at least a month before.

Stopping

  • Time of day doesn't really matter in stopping the car. It might affect your reaction time if you have vision troubles, but it doesn't affect the actual stopping the car, the weight, the speed, the condition of the road, your brakes, your tires, all of those things will have an effect.

Random

  • Velocity^2: whatever your speed is, if you double your speed, it is four times as much. If your speed is four times as much, then the energy and the damage is 16 times as much. It goes up incredibly quickly.

TDA

  • Student portal will be the first place to look for everything. Then, calling will be the last resort.

Highway Driving

  • You are less likely to get into a crash on the highway than anywhere else. But because of the higher speeds involved when there is a crash, they tend to be more deadly. So most of the deadly crashes do happen on the highway.

  • On the highway, keep track of the traffic. It is a little bit more important on the highway than on a regular road to keep track of what's going on behind you.

  • Avoid aggressive drivers because they do not think they need to be taught how to drive and that they know what they are doing.

Merging

  • The thing you need to do is get your car up to the speed of the highway. If you are trying to merge into traffic and you are going about the same speed as them, you can very easily find a space to to merge yourself in.

  • Put your turn signal on right before the curve, and right before the curve, you're looking down the highway and you're you're already trying to spot a place where you might be able to fit your car. Step hard on the gas and you accelerate. The goal is to get up to highway speed before you get to the end of that merging area.

  • Slowing down is dangerous because speeding up is safe.

Merging Traffic

  • The responsibility belongs to the traffic who is merging.

Tailgaters

  • If there is a tailgater, you want to move out of their way. You do not want to teach them how to drive. Leave it be.

Stop and Go Traffic

  • If everybody was leaving three seconds of following space, you would have far fewer traffic jams.