Final answer:
The sight distance required at two-way stop controlled intersections for minor street movements depends on driver reaction time, vehicle speed, and road conditions. It is critical for safety to allow adequate time for drivers to react and stop their vehicles. Traffic speed and pedestrian visibility must be considered to determine if crossing is safe.
Step-by-step explanation:
At two-way stop controlled intersections, the sight distance required for minor street movements is determined by several factors including driver reaction time, vehicle speed, and road conditions. Sight distance is essential for safety as it determines how much time a driver has to react and stop their vehicle to avoid collisions. For instance, if a car is initially traveling at 30.0 m/s and the road is dry, the braking distance will be different than on a wet pavement due to varying traction.
Additionally, if we assume a reaction time of 0.500 s, the car will travel a certain distance before the driver even begins to apply the brakes. Coming back to the scenario of the student, Bridget, who times cars on a 50 m stretch taking 3 seconds to travel between two poles, she can estimate the average speed of traffic, which can be associated with typical stopping distances.
Knowing that many vehicles speed through the intersection, it reinforces the need for a safe stopping sight distance for those coming from minor streets. As for pedestrians, ensuring they are seen at an appropriate distance is also crucial for their safety when attempting to cross the road. The question about whether it is safe to walk across the road if a car is 28 m away — the equivalent of 8 car-lengths — would depend on the car's speed, the observer's reaction time, and the road conditions.