This document discusses reaction distance and braking distance when driving. It provides formulas to calculate both. For reaction distance, it is estimated as d = 1.1 x r, where d is distance in feet and r is speed in mph. For braking distance, it is estimated as b = (r/30) x F, where b is braking distance in feet, r is speed in mph, and F is a driving surface factor table provided. It then gives an example calculation for estimating reaction and braking distance for a driver going 50 mph on dry asphalt.

1. reaction & braking distance January 31, 2013
Objective: Calculate reaction and braking dist
16.13 mph
14.25 mph
12.59 mph
11.62 mph
Jan 30­5:48 PM
HW wkst pg. 241 #1­23 1

2. reaction & braking distance January 31, 2013
Reaction Distance:
distance a car travels during the time it takes a driver to
brake the car.
You can use the following formula to estimate reaction distance.
d = 1.1 x r d = reaction distance in feet
r = speed in mi/hr
Example 1: Dan is driving at 50 miles per hour on a dry asphalt road.
Estimate the reaction distance.
Jan 30­6:13 PM
HW wkst pg. 241 #1­23 2

3. reaction & braking distance January 31, 2013
Braking Distance:
the distance traveled by a car after the driver brakes and unt
the car stops completely. You can use the following formula to estimate bra
distance.
b = x r
r b = braking distance in feet
30 x F F = driving surface factor
Example 2: Use the table to estimate Dan's braking distance from Example
nearest foot.
Type of Driving Surface Factor
Surface
Dry Road Wet Road
Asphalt 0.85 0.65
Concrete 0.90 0.60
Gravel 0.65 0.65
Packed
0.45 0.45
Snow
Jan 30­6:18 PM
HW wkst pg. 241 #1­23 3

4. reaction & braking distance January 31, 2013
Worksheet pg. 241 #1­23 a
Jan 30­6:27 PM
HW wkst pg. 241 #1­23 4