In an effort to reduce Motor Vehicle Accidents that involve Fatalities and/or Severe Injury, the Chattanooga Department of Transportation and the Police Department have teamed up to identify trends in MVAs and what evidence based treatments they can do to help prevent them. CDOT can work to implement traffic calming, access to sidewalks/bike lanes, and improved lighting in areas where MVAs occur; and CPD can work to implement targeted enforcement, community awareness campaigns, among other initiatives.
Things We Look At
- Locations of accidents - where are the MVA hotspots?
- Times of accidents - when are MVAs occurring?
- Circumstances of accidents - is there a common thread, alcohol involved, seat belt usage, etc.?
- Are there drivers in certain areas that are more at risk of being at fault?
CDOT and CPD are measuring Pedestrian, Bicycle, and Vehicle fatalities in an attempt to collaboratively reduce instances of fatal accidents. Though this is a difficult goal, the overall idea should still be continually pushed as fatal incidents are an avoidable tragedy and a significant cost to society both emotionally and fiscally. The below numbers are cumulative counts of fatal vehicle incidents, not total fatalities. One fatal incident may include multiple fatalities, but it will still only be counted as one.
Multi Vehicle Accidents Map
The map below shows all Multi Vehicle MVAs occurring the current fiscal year. Areas in red indicate a high frequency of MVAs, but the intersection of Amnicola and Wisdom contains incorrect data to to reporting errors setting the address of the incident at the police station. As expected, many MVA occur downtown and on major roadways.
Single Vehicle Accidents Map
The map below shows all Single Vehicle MVAs occurring the current fiscal year. Areas in red indicate a high frequency of MVAs, but the intersection of Amnicola and Wisdom contains incorrect data to to reporting errors setting the address of the incident at the police station. Based on the map, there seems to be a high rate of single vehicle accidents around the ridge-cut and I-24/I-75 split among other locations.
Serious Injury or Fatality MVAs
The map below shows Serious Injury and Fatality MVAs the the past year since today. Selecting each dot will provide further information on the incident.
Fatal Incident Alcohol Involved
To the right, a simple pie chart shows 40% of fatal vehicular incidents involved alcohol. Alcohol usage significantly impacts a drivers ability to see, react in time, coordinate, concentrate, among many other impairments thereby leading to an increased risk of being involved in an incident.
All MVAs by Time and Weather
The below chart shows peak accident times for the past year since today. Peak times are from 3pm to 6pm. Overall, weather does not seem to have too much of a significant effect in regards to day or night. Select filters below to drill down deeper.
All MVAs by Speed and Weather
The below chart shows the impact speed and weather can have on incidents. The speed is only the posted speed limit, as it is not possible most of the time to know the actual speed of the vehicle involved.
At Fault Drivers
In CPD, Sworn officers are trained to label the at fault driver as driver 1 in the police incident report. Though this may not always be the case due to improper entry or the circumstances of the vehicle incident, it is a safe assumption to make. The below chart is the count of vehicle incidents by Driver 1 (typically at fault driver) ZIP Code for the top 10 by number of incidents. The two highest are clearly ZIP codes 37421 and 37343. This is mostly due to a higher population within these ZIP Codes relative to others, age distribution differentials, and the fact that drivers from these ZIP Codes often commute into downtown Chattanooga for work (as evidenced by the heatmap further below).
Driver 1 ZIP Code Heatmap
It's also important to understand where these accidents are occurring based on the ZIP code location of driver 1. This way, we can see if there are trends in where at fault driver's from ZIP codes are driving. The default to the right is set to the highest number of incidents by ZIP code, which is 37421; but clicking the drop down, other ZIP codes can be chosen. For all ZIP Codes, it appears a majority of incidents occur within the ZIP code, as is expected.