Traffic Operation and Accident Investigation
Traffic - may consist of pedestrians, ridden or herded animals, vehicles, street cars and other conveyances either singly or together while using the public way for purposes of travel.
Traffic laws - laws which govern traffic and regulate vehicles.
Traffic signs/road signs - are signs erected at the side of the roads to provide information to road users.
Rules of the road - are the laws and the informal rules that may have developed overtime to facilitate the orderly and timely flow of traffic.
Right of way - is a strip of land that is granted, through an easement or other mechanism for transportation purposes such as for a trail, driveway, rail line or highway.
- the legal right, established by usage or grant, to pass along a specific route through property belonging to another.
Traffic signal/Traffic light - a visual signal to control the flow of traffic at intersections.
Highway - any public road. A main road especially one connecting major town or cities.
Speed limit - define the maximum, minimum or no speed limit and are normally indicated using a traffic sign.
Hit and run - is the act of causing a traffic accident and failing to stop and identify oneself afterwards.
Traffic accident - occurs when a vehicle collides with another vehicle, pedestrian, animal, road debris or other statutory obstruction such as tree or utility pole.
Mary Ward - worlds first road traffic death including a motor vehicle, is alleged to have occurred on august 31, 1869, when she fell out of her cousins steam car and was run over it.
Causes of traffic accidents
Skid mark - is the mark a tire makes when a vehicle wheel stops rolling and slides or spins on the surface of the road.
Skid mark are divided into:
RA 4136 - Land Transportation and Traffic code of the Philippines.
Coefficient of Friction - is a dimensionless scalar value which describes the ratio of the force of friction between two bodies and the force pressing them together.
Rail Adhesion - grip wheels of a train have on the rails.
Split Friction - dangerous condition arising due to varying friction on either side of a car.
Road Texture - affects the interaction of tires and the driving surface.
Profilograph - devised used to measure pavement surface roughness.
Tribometer - an instrument that measures friction on a surface.
Traffic Waves - "stop waves" "traffic Shocks" - are traveling disturbances in the distribution of cars on a highway.
Traffic Flow - the total number of vehicles passing a given point in a given time. Traffic flow is expressed as vehicle per hour.
Traffic Congestion - "traffic jam" - is a condition on roads, streets or highways that occurs as use increases.
Characteristics of Traffic Congestion
1. Slow speed of vehicles
2. Longer travel time
3. Increased vehicle queuing
Classical Theories of Traffic Flow
1. Free flow
2. Congested traffic
Three-Phase Traffic Theory - is an alternative theory of traffic flow developed by Boris Kerner between 1996 and 2002.
1. Free flow
2. Synchronized flow
3. Wide moving jam
Pedestrian - is a person traveling on foot whether walking or running.
Gridlock - a traffic jam so bad that no movement is possible.
China - (Beijing-Zhangjiakou province) - is considered the worlds worst traffic jam ever as traffic congestion stretched more than 100 kilometers including 11 days of gridlock.
Brazil - (Sao Paolo) - has the worlds worst daily traffic jams.
France - (A6 Auto-route) - between Paris and Lyon was considered the worlds longest traffic jam.
Related Readings: Traffic Operation and Accident Investigation
1. Traffic Operation Definition of Terms
2. Traffic Operation and Accident Investigation Reviewer 1