It can take a lot of information to analyze a crash. Data gathering should begin as soon as possible.
Witness testimony is often the best tool to analyze a crash. Witness location most be established, as well as what was visible to the witness. Witnesses can help show traffic patterns- light or heavy in a particular direction, backed up into the intersection, etc., as well as the presence of other vehicles or pedestrians, and the direction of travel of any other traffic.
Witness
Witness can tell an investigator about a crash. 1. How long the witness had been stopped there? 2. What was the condition of “all” of the traffic signals when the witness arrived at the intersection (through, left turns, pedestrian phases)? 3. When did the left-turning vehicle arrive? 4. What was the condition of the traffic signals when the left-turning vehicle arrived? 5. What happened when the northbound lights changed? 6. Did the through (green ball) light and left turn lights change together?
Traffic experts can do studies of the traffic patterns
Traffic experts can do studies of the traffic patterns in order to determine whether signals are needed at an intersection, and how the signals should be set. Such a study will often involve a “traffic count” to find out how many vehicles are turning left, going straight, or turning right at an intersection. Traffic patterns change over the course of the day, a traffic count will involve tracking traffic over a pre-determined time period. The movements with the largest number of vehicles in their respective direction will receive more green time in the cycle in order to accommodate the traffic pattern. Timing data can be changed at different times of day in order to accommodate heavy traffic flow in particular movements.
Pedestrian “Walk” and flashing “ Don't Walk” times
pedestrian “Walk” and flashing “Don't Walk” times are set using controller timing parameters. Seven seconds is often used for walk intervals, this allows time for the pedestrian to walk from the sidewalk and into the crosswalk. This time may be enlarged to accommodate heavy pedestrian traffic situations. The flashing “DON’T WALK” period is calculated to allow the pedestrians to walking across the street . The standard walking speed used for the timing calculation is 4 feet per second. Therefore a crossing distance of 60 feet, requires 15 seconds the time allocated to the flashing “Don't Walk” phase would be approximately .
If you have been injured and a traffic signal is an issue in your case you should see a lawyer and that lawyer should retain an accident reconstruction expert.
