What the Data Says: Putting Safety First

A version of this article was originally featured in SEMCOG’s Putting Safety First. It illuminates regional data that underscores the gravity of fatal and serious crashes in Southeast Michigan. As we reflect on the many lives impacted by preventable tragedies, it becomes evident that concerted action is imperative. SEMCOG’s Southeast Michigan Transportation Safety Plan identifies key safety needs and guides investment decisions to eliminate fatalities and serious injuries for all road users.

Southeast Michigan averages over 100,000 traffic crashes per year. As illustrated by the Crash Location map, it would be an almost-impossible undertaking to analyze every crash and determine how it could have been prevented. It would also be inefficient toward our primary goal of saving lives. While inconvenient, frustrating, and often scary, the vast majority of crashes observed in our transportation system are non-life threatening.

To reduce fatal and other serious crashes, SEMCOG has identified key factors that are prevalent in fatal and serious crashes. When one or more key factors or emphasis areas are involved in a crash, the likelihood of severity increases. The more key factors that are present, the more potentially dangerous the crash. By analyzing the data, we can see which factors are most highly correlated to crash frequency and crash severity. As seen in the graph on the right, crashes involving intersections rate very highly in both frequency and severity.

William Miller, Commissioner, Oakland County, Michelle Nard, Commissioner, Macomb County, and Alex Bourgeau, Manager, Transportation Modeling and Mobility, SEMCOG discussing SEMCOG’s Safety Plan at a SEMCOG Executive Committee meeting.

How the COVID-19 pandemic impacted transportation safety in Southeast Michigan

• Crashes resulting in fatalities and serious injuries have increased. Despite a lower number of crashes from 2020-2022 compared to pre-pandemic levels, crashes were more severe with higher fatality rates and serious injury rates.
• Speeding-related fatalities have reached their highest levels in the last decade. Speeding crashes were the lowest since 2013; however, the number of fatalities has been increasing each year since 2017, reaching its highest in 2022 with 83 fatalities.
• Intersection-related fatalities reached 10-year high during 2020 with 152 fatalities.
• Vulnerable road user crashes continue to be a serious issue in the region. In both 2021 and 2022, pedestrians were involved in less than 1% of all traffic crashes but accounted for 19% of all traffic fatalities; the top two years for bicyclist fatalities occurred in 2020 and 2022 despite the downward trend of number of crashes since 2016; motorcyclist fatalities also reached a 10-year high in 2022.

Crash Location Map

SEMCOG’s crash location map represents locations of reported crashes on roads in Southeast Michigan. The map has been updated to include 2022 crash locations. The data can be filtered by year and the available years are 2018 to 2022. The “crash bin summary” enable you to see key data and crash factors to enable decision-making.

SEMCOG’s multimodal tool provides performance metrics for all types of road users, instead of just automobiles

SEMCOG and the Michigan Department of Transportation (MDOT) developed the Multimodal Tool to assist communities in Southeast Michigan with determining modal priorities for streets and evaluating how current and planned designs work for all road users using quantitative performance measures. This is an important tool for implementing the Safe System Approach because it helps planners and engineers evaluate the needs of all road users, especially the most vulnerable.

The Multimodal Tool was prepared with the following objectives:

• Address growing competition between travel modes for limited space within the right-of-way;
• Help local communities understand what is permitted for each project and road jurisdiction; and
• Provide a framework for communities to work with SEMCOG and MDOT to determine the order in which modes may be prioritized on certain corridors or within a district, and to work within operational standards.

Recent legislation: speed setting law

HB 4012, approved by the Governor on April 2, amends the Michigan Vehicle Code to give local communities more flexibility to account for safety hazards for all road users when setting speed limits. Now, speed limits “must be determined in accordance with traffic engineering practices that provide an objective analysis of the characteristics of the highway” and “may be set below the eighty-fifth percentile speed if an engineering and safety study demonstrates a situation with hazards to public safety that are not reflected by the eighty-fifth percentile speed”. Setting appropriate speed limits considers factors like land use context and the pedestrian and bicyclist activity in the area.

SEMCOG was engaged with and supported the bill. It implements the policies and actions of the Southeast Michigan Transportation Safety Plan. The plan is organized around the five elements of the Safe Systems Approach: Safer People, Safer Roads, Safer Vehicles, Safer Speeds, and Post-Crash Care. The Safer Speeds regional policy is to promote safer speeds in all roadway environments through a combination of thoughtful, context-appropriate roadway design, targeted education and outreach campaigns, and enforcement. Regional actions include setting context-appropriate speed limits and supporting legislative efforts to improve behavior and safety for all road users.

Tools to support decision-making

High Injury Network

This map identifies road segments where fatal or serious injury crashes have occurred over five years of data. The Southeast Michigan Transportation Safety Plan plan also breaks down the network further by road jurisdiction and facility type (based on speed limit, number of lanes, etc.) to identify focus facilities for project prioritization.

Excess Capacity

This analysis identifies locations where daily traffic demand is lower than the available roadway capacity. These locations have potential for traffic calming, such as a lane reconfiguration or road diet (a FHWA proven safety countermeasure for reducing fatalities and serious injuries because overbuilt roads encourage higher speeds and reckless behavior).

Transportation Equity Areas

The goal of transportation equity is to facilitate access to opportunities by providing safe, affordable, and reliable transportation options based on the needs of the people they serve. There are certain populations with greater social and economic needs, or disabilities, that may impact their mobility options. This is another useful tool for prioritizing transportation projects that will not only reduce fatalities and serious injuries, but also positively impact disadvantaged communities.

Speed Data

Safe speeds are integral to a safe transportation system. This web-based software can display maps and data at road segment levels for three types of speed data:

• percent of vehicles over speed limit (user-defined)
• percentile speeds
• speed limit

Users can analyze and compare the speeding or percentile speed data by time of day, day of week, plus day of week combinations, and user-defined routes. Reports and charts can be generated and exported in various formats. Technicians and planners can conduct before-and-after analyses on speeding hotspots where countermeasures have been deployed.

Coming soon

A Transportation Safety Hub is in development and can be accessed in the near future from SEMCOG’s safety webpage. It will have online interactive versions of these analyses and other resources from the Transportation Safety Plan.