2. Car Accidents & Cell Phones By:Hongtao Xu Sasha Hochstadt Logan McLeod Heather Samoville Christian Helland Meng Yu

3. Objective  Why? Recent Legislation Is it Valid? Justifiable?  What? To determine a possible correlation between traffic fatalities and cell-phone users  How? Collect data of traffic fatalities and cell-phone subscription Setup valid model and find relationship between them

4. Initial Hypothesis –Traffic accidents are increasing over time –After the introduction of cell phones traffic accidents will increase at a higher rate

5. Gathered Data Estimated # of Cell Phone Subscribers 1985-2002 Traffic Fatalities 1966-2000 # of Registered Vehicles 1966-2000 # of Licensed drivers 1966-2000 Resident Population 1966-2000 Fatality Rate per 100k Registered Vehicles 1966-2000

8. Modified Hypothesis Findings: –Fatalities from car accidents are actually decreasing over time –Cell phone subscribers are increasing exponentially over time  As fatalities continue to decrease over time, the introduction cell phones will cause them to decrease at a slower rate In order to show this we must compare the periods before and after cell phone use

9. Before Cell Phone Use After Cell Phone Use Fatalities as a Function in % Change of Cell Phone Subscribers Year LN(Fatalities) Error

10. Before Cell PhoneAfter Cell Phone Annual Motor Vehicle Fatalities per Registered Vehicles

11. LN(FATALITY) = 75.5532 - 0.0364069*YEARLN(FATALITY) = 53.4660 - 0.0252678*YEAR Before Cell PhoneAfter Cell Phone Regression Results in time series

12. Quantifying the Cell Phone Effect Extrapolate pre-cell phone regression into cell phone regression Calculate expected # of fatalities and % difference from actual Find relationship between % error and # of cell phone subscribers

13. Region of Dramatic Deviation from Expected Values.

15. Results FATALITY = -1.309 + 0.08443*LOG(CELLPHONE)

16. Results

17. Conclusions A strong correlation between cell phone subscriptions & fatality rate exists. Our model exhibits a logarithmic relationship. We estimate that since 1991, cell phones have caused more than 40,000 deaths.

18. Questions?