INTERSTATE FATALITIES Presented to you by Bob & Chuck
The PA Department of the US National Highway Traffic Safety Association Analyze & Study recent National Roadway conditions Different types of Roadways (interstate vs. non-interstate) Various speeds 51 states in the U.S
FATALITIES That occurred in CAR CRASHES
Many states report that the numbers of fatalities increases as the speed limit increases. Question: Can you really be certain that there are more accidents at higher speeds. Are there more fatalities on High speed roadways or low speed roadways dealing with only non-interstate roadways? TWO-SAMPLE HYPOTHESIS TEST NULL: ALTERNATIVE: There are not more fatalities on High speed roadways than Low speed roadways There are more fatalities on High speed roadways than Low speed roadways T-OBS > t-critical ? YES P-value < ά-level ? YES We will REJECT the NULL, Proving that there are more fatalities on High speed roadways than low speed.
Comparison of Fatalities in the 50 States 395 3304 *The District of Columbia did not report any Fatalities
Is the graph misleading? Reject the Null
Conclusion Greater Speeds increase the likelihood of a fatality. PA numbers appear to be similar to numbers across the country. Fatalities occur more often on Non-interstates road ways than interstate road ways. …or do they?
Further Contemplation Why do fatalities appear to occur at a higher rate on Non-interstate roadways? www.fhwa.dot.gov
Is the Graph misleading? Reject the Null
Final Conclusion Although more fatalities are reported on Non-interstate roadways, it appears that mile for mile there is a greater possibility of a fatality on an interstate road way. Recommendation Categorizing Non-interstate roads as “More Dangerous” can lead to reduced caution in the more often high speed situations that require it. Consider lowering speeds on Non-interstate roadways to decrease the likelihood of fatal accidents. While attempting to create safer conditions and greater driver awareness, remember to emphasize driving responsibly on all roadways.