Traffic Logic: If the vehicle pokes out into the road, the space available for cross traffic to move past is reduced. Vehicles in cross traffic have to move closer to each other. To do this safely, they have to slow down. They will take longer to go past your vehicle than if you waited a little further back, and you will have to wait longer.

Rule: Vehicles are not permitted to cross the STOP line at traffic signals.

Traffic Logic: The STOP line is marked before you reach the zebra crossing. If vehicles cross this, they poke into the space for pedestrians to cross. Pedestrians will have to slow down to go between vehicles. They may not finish crossing the road before the light changes. Vehicles have to wait for them, which can cause traffic jams.

Priorities: Who should give way to who is set by road rules? This applies to all vehicles, irrespective of size. I.e., the bigger vehicle does not always have priority!

Rule: On straight roads or unregulated crossings, give way to traffic on your right.

Traffic Logic: (a) Faster traffic moves on the right of the road (furthest from pedestrians). It is easier for slower vehicles to stop than faster vehicles.

(b) Driving, we sit on the right side. Thus, it is easier to see vehicles on the right than the left. So, if you are to the left, you give way. If you are to the right, you have right of way. E.g. if you are on the left and want to turn right, and a car is coming up behind you on the right, slow and wait for it to pass before turning. If you can’t “see” him on your right, he surely can’t “see” you on his left!

Driving at Intersections: Straight traffic gets priority over turning traffic.

Traffic Logic: You have to slow down for a turn anyway. It is easier to stop when slower. This is true for both straight roads and crossings.

Rule: Main road traffic has priority over side road traffic.

Traffic Logic: Main road traffic is faster than side road traffic. Main roads are also more crowded. If main road traffic stops for side road traffic, there will be a jam. Side roads rarely have enough traffic to cause a jam.

Rule: If the driver is to leave the roundabout less than halfway around it, the driver must enter the roundabout from the left marked lane or left line of traffic.

Traffic Logic: This rule applies to drivers who will leave the roundabout at the first exit after entering the roundabout, or when the exit is less than halfway around the roundabout. By keeping to the left lane and keeping the left turn indicator on during this time, the driver is saved the trouble of first switching to the right lane and then working his/her way back to the left.

Rule: If the driver is to leave the roundabout more than halfway around it, the driver must enter the roundabout from the right marked lane or right line of traffic.

Traffic Logic: By switching to the right lane immediately after entering the roundabout, a driver who has to travel at least halfway around it is saved the trouble of negotiating around other drivers who are exiting the roundabout, and those who are entering the roundabout from other intersection points.

Rule:  On T junctions, traffic going straight gets priority.

Rule: Certain roads have marked speed limits. You are not permitted to exceed this speed.

Traffic Logic: Speed limits are set based on traffic conditions on that road, to ensure road safety. E.g., highway speed limits are quite high, while in school areas they are low. In India, the design speed of highways is 60 km/h. It is not advisable to exceed this speed on turns. Speed limits on divided urban roads are usually 45 km/h for cars. On undivided roads, this may be 30. Residential areas are 25 km/h unless there is a sign stating otherwise. Exceeding the speed limit endangers pedestrians and other road users, as well as the speeder. The faster the car, the more the chances of a crash, and the more severe the injuries and property damage. Some weak bridges also have low speed limits, as a faster vehicle puts more load on the structure. If visibility is low, e.g. at night or in rain/fog, it is advisable to stay 10 km/h below the daytime limit.

Rule: You are not allowed to use a cell phone ("mobile") while driving. 

Traffic logic: Both your hands and your attention are distracted when you are using a cell phone. You cannot pay sufficient attention to the traffic, and may cause a crash. You are therefore liable to be challenged for this.

Hands-free: These sets are more critical as that your attention is still distracted, much more than talking to others in the car. Some researches rate it as at par or more dangerous than drunk driving.

It is best to switch the phone to voicemail or off while driving. If not, get a passenger to take your call, or disconnect, find a safe place to stop (off the road or on the side if permitted ), and return the call.

Courtesy: While calling up someone on the mobile, always ask first: "Are you driving?" (Even before "Are you busy?") If the answer is yes, disconnect and call back later.

Emergency vehicles

Rule: Emergency vehicles (fire engines, ambulances, and police; with red/blue flashing light and/or siren) get complete priority over all other traffic. Give way, even if the traffic light is against them and in your favour.

Traffic logic: Obvious! They are rushing to save lives; you are not.

Courtesy: Pull over to the side of the road immediately, and stay there till they have passed. Never attempt to cut traffic lights in their wake. This is illegal, anyway.

Non-emergency vehicles

Rule: It is not permitted to use a siren (or siren-like horn) on a non-emergency vehicle. This is a punishable offence.

Traffic logic: Remember the boy who cried “Wolf!”? If people get fooled by fake sirens, they may not give way when it is really required.

Courtesy: Give way to high officials with red lights on the car (no siren), as soon as convenient. However, this is not obligatory.
One way roads

Rule: Certain roads are one-way only. It is not allowed to go the other way on such roads, even in reverse gear. One-way roads are indicated by many signs, besides ‘One-way’, e.g. ‘No entry’, ‘No right turn’ or ‘No left turn’. Traffic can only exit at this point, not enter. ‘Compulsory right turn’ signs mean the same as ‘no left turn or straight’, etc.

Traffic logic: This is required to prevent collisions. Reversing on such roads is worse than driving in the wrong direction, as you won’t even be able to easily see what you are backing into!

Rule: To reach a cut in the road which is to the right of the point at which you reach a road with a central divider, turn left, and do a U-turn at the next cut to the left. This applies no matter how close the cut to the right is, or how far the cut to the left is.

Traffic logic: Turning right puts you on the wrong side of the road, and increases collision risk. If no cut has been provided, it is that the main road traffic is too heavy to cut across. Turning left allows you to join the traffic easily, and the distance to the cut on the left gives you enough time to find a break and move to the right side, so that you are in place for the U-turn.

Intersection logic

Rule: Turning left, doing a U-turn and turning left again, to avoid a red light, is treated the same as jumping a red light, and gets the same fine.

Traffic Logic: While doing the U-turn, you would be cutting across the same traffic that the red light was stopping you from, with the same risks.

Rule: You are not allowed to do a U-turn at an intersection where opposing traffic is also ‘green’. Busy T-intersections either have a U-turn signal on the straight leg, or a ‘No U-turn’ sign. If so, take the left road, do a U-turn at a cut or circle (not an intersection), and take the right at the signal.

Traffic Logic: Due to the turning radius, you would cut across the entire on-coming traffic, which is not safe.