Conclusion

Based on our findings, we observe that the number of charging stations is strongly correlated with the EV population in the area. Moreover, we found a moderate correlation between the education levels of the population and the number of electric vehicles and charging stations in the area. Income levels don't appear to have a significant impact on either the number of electrics vehicles or number of charging stations. Moreover, our observations showed that the majority of the charging stations are located in the downtown area versus the suburbs where most of the vehicles are registered. It is very convenient for the people who work in downtown, however, it complicated our research since it was harder to find a correlation between charging station locations and counts of EV cars. Changing the granularity to the "city" level from the "zip code" helped us to solve this issue for the most part. While in average the correlation between EV population and charging stations is high, we have identified that there are some cities where the relative number of charging stations are low compared to the EV population. This suggest that the supply is low compared to demand and therefore they are good candidates for the addition of more charging stations.

Determining the best location and the adequate number of charging stations is a very complex question that can not be identified by 2-3 variables. Prior research also showed that multiple factors including electricity source availability and freeways' proximity should be taken into account when choosing the EV station location. 

Some of the variables that could be taken into consideration for further research are population density around the proposed location, age distribution, and unemployment rates among the population. Government incentives and Zoning planning should also be considered as possible factors affecting the number and location of charging stations in the area.