Unit sec 2.2

The highway code might have been developed, by following the 4 stages of the modelling cycle.

   Stage I: clarify the question

Both models have been constructed in order to answer the question:

“what gap between your vehicle’s should be recommended for drivers travelling at different speeds?”

    Stage II making assumptions and collect data:

the distance model is based on typical stopping distances at various speeds. It has been assumed that the stopping distance is determined by 2 factors:

v the thinking distance (the distance travelled from when the driver first see hazard until he or she applies the brakes.)

v The braking distance (the distance travelled from when the brakes are first applied to the point when the vehicle stops.)

      The experiments would probably produce a range of possible times, depending on the individual and their state of alertness. It is possible to determine a typical reaction time.

   The model ignores other features of the situation such as the road surface, the make and weight of the car, the weather conditions and the tiredness of the driver.

Stage III using mathematics to obtain results

the next stage is to use some mathematics, nest case of working out the distance by using formulas.

The car is likely to be travelling at a consistent speed. If you know the speed of a vehicle and the time during which it travels at that speed, then you can calculate the distance it travels. In general if an object needs for a certain period of time, then the distance it covers in this time is given by the following formula.

Distance = average speed × time

This speed by using the data collected to Derive a more complicated formula. Roughly speaking, the effect of the formula is that the speed it doubles, then the braking distance quadruples.

Stage IV interpret and check the results

the distance model could be checked with the reality by, o of whether drivers managed to stop their vehicles within the “typical stopping distance” and also whether collisions occur less frequently when driving to keep this gap between their vehicle and the next.