Intersections Safety : Identifying Gaps : A Thread 🧵
Intersections are the places where the direction of vehicles intersect,with many conflict points from all sides.
It's essential to know how to handle them.
Many accidents happen in cities/highways at intersections.
Most of the risk is eliminated by using signals,but there are uncontrolled intersections at many places in cities and highways,which require skill and practice to cross safely.
To cross them safely we need to identify gaps that allow us to pass through them, without an accident.
A defensive driver looks for safe gaps which allows him/her to cross the intersection without letting other drivers brake or swerve or take an evasive action.
This comes by practice and we need to increase our observation skills to find safe gaps.
At uncontrolled intersections, we will either take 1. left turn 2. right turn 3. straight 4. U turn
All 4 moves require different amounts of time required for safe movement.
Let's study the situations.
Left Turn :
The left turn is less complex but we need to give way to pedestrians.
Once we complete the turn,we should move at the same speed of traffic behind or they have to brake or change lanes.
So,we need at least 6 seconds of time for completing the turn and acceleration.
Right Turn :
In the right turn, we have to cross 2 lanes on opposite sides so we need to be more attentive and need more time.
We need at least 10-12 seconds to safely make a right turn.
In cities,you may get away with less impact but on highways,there is no second chance.
How to estimate the time ?
Go to a busy intersection,park the car somewhere and observe vehicles from a distance. See how much distance they covered in 6-12 seconds to find out,how far they were.
Now, you will have an estimated distance. At higher speeds, increase time required.
Finding gaps is an essential skill and defensive drivers must practice good observation skills. Give extra time for yourself if required and it's totally worth it.Reaching destination safely is more important than losing a few seconds at the intersection.
Fog is the most hazardous of all driving conditions encountered in India and its essential to know how to handle it safely.
Fog reduces visibility drastically and we lose almost our peripheral vision and due to lack of contrast with the surroundings, there's scope for dangerous crashes.
However, scientific insights are always there to rescue us from the toughest conditions and let's learn them.
Fog and Tyndall Effect : Fog is a suspension of tiny water droplets in air that reduces visibility. When light falls on the suspended water droplets, it scatters and reduces visibility to drivers.
Fog can be seen in winters and very common in Northern part of India.
Challenges in Fog :
1. Reduced Visibility - Drivers may struggle to see vehicles, road signs, lane markings, or pedestrians.
2. Difficulty in judging distance - our brain perceives that the objects that are not clear are far off and objects that are clear are closer. With fog, objects that are closer to us is perceived to be far due to the reduced visibility and there is a crash risk.
3. Speed Judgement - Lack of contrast with the surrounding environment which may make us believe that we are driving slower and may unintentionally speed up
We cannot react to a hazard, if we can't see them.
This problem unfortunately didn't get much attention but it is one of the high risk scenarios where crashes happen at low speeds and at areas which are familiar to the driver and most often, the victim is known as well.
With the growing number of vehicles in India and with a poor town planning, its essential for drivers to understand the risks.
The video is a compilation of all such crashes in India in the last few years.
Let's get into the details.
In most cases, its the responsibility of the parents to take care of the child but we have seen occasions where parent or someone who's so close to the child had driven over the child as they couldn't see the child.
So, its essential for car drivers to know the risk and develop a strategy to minimize the risk.
We cannot react to a hazard, if we can't see them.
Why can't drivers see them? Blind Zones around the car cover a large area, which most drivers are unaware. The larger the car, the larger the hidden area.
Many crashes on undivided roads happen while failing to estimate the speed of oncoming vehicles and attempting an overtake by going to the opposite lane and crashing head-on.
Most often we meet the oncoming vehicles at the mid point between us from the time of first sighting of the oncoming vehicle.
A head-on collision is the most dangerous form of crashes and if passengers are not wearing seatbelts,there's an increased risk of loss of lives.
#UndividedRoads
#DriveSmart
As per road craft, here's the safe approach for overtaking.
Avoid doing it when there are oncoming vehicles.
Avoid overtaking on undulated roads until the line of sight is clear.
Avoid overtaking on curves.
Avoid overtaking where there's a sign of "No Overtake"
Let's use this example to study the situation.
My speed would be around 40-50 kmph there.
We see a bus at the horizon coming from the opposite side.
As per the timestamp on the dashcam,me and the bus crossed each other in 10 seconds.
Video in the tweet below 👇
Recently,we saw so many accidents involving overspeeding on curves by overloaded vehicles,understeered vehicles resulting in fatal accidents etc.
Having a knowledge of tyres and how they work is essential to drive safely.
Tyres can do one thing to a maximum 100% efficiency. If they need to do two or more things then they have to share that ability. This is called tyre grip trade off. Therefore, if the vehicle is travelling in a straight line the front tyres need only steer.
Source : Roadcraft
If the vehicle needs to slow down then the tyres need only brake. If the vehicle is on a curve and you need to apply the brakes then clearly the tyre has to do two things - steer and brake. This means it cannot do either to maximum efficiency.
This video went viral yesterday.
As a defensive driver can Xylo avoid it? 1. It's a left hand curve part of S curve 2. Xylo has the risk of moving to the other lane if his speed is more for that left curve 3. The bus crossed double yellow,which Xylo didn't expect 4. Parked cars
Expecting people to obey double solid lines is a big mistake.
To avoid crossing double solid lines, vehicles must reduce speed at such curves, or there's a risk of crossing due to understeer or oversteer.
Better Action:Reduce speed before entering curve,give an exit route to bus
What is common in these 2 videos shared by @CYBTRAFFIC ?
Why did the bikers hit the pedestrians as if they're the target 🎯?
This is a psychological phenomenon called "target fixation" and can happen to the best of us.
Let's see strategies to avoid it.
A short thread 🧵