- Traffic Intersections and their Safety Hazards
- Safe System Designs for Road Intersections
- How Driving Data can Support Proactive Road Safety at Signalized and Unsignalized Intersections
- MICHELIN DDi’s Expertise in Safer Roads at Intersections
Through their very function and design, intersections create the conditions that can lead to car crashes and near-crashes. Of the 36,835 road fatalities that occurred in 2018, almost a third were at intersections – 3,274 at signalized intersections and 6,737 at unsignalized intersections. Intersections are where drivers and other road users can change directions, where several different kinds of road users meet, and where each flow of users needs to be sequenced in a way that respects everyone’s needs. Analyzing drivers and their behavior can help to illuminate the safety risks at any intersection – signalized or unsignalized, major or minor, urban or rural – through the identification of near misses.
Traffic Intersections and their Safety Hazards
According to the Federal Highway Association (FHWA), the seriousness of an intersection car crash depends on variables such as intersection design, vehicle speed and collision angle.
Four-Way, Highway, Controlled: Intersections are Meeting Points – and Conflict Points
Intersections are essential road assets where drivers, public transit, pedestrians and cyclists congregate and disperse for the entire length of their trip. Meeting each other at a crossing, a traffic light or a roundabout intersection naturally leads to conflict, from who has right of way to how users navigate the intersection. Design can greatly influence the potential number of points of conflict, from 32 at a standard, two-lane by two-lane cross intersection, down to eight at a roundabout.
Speed at Intersections
Higher vehicle speed leads to greater energy release and more serious car crash consequences. Intersection design influences the speed at which road users pass through them: the bends in a roundabout or a red traffic light forces drivers and users to slow down or stop. Signals and stop or yield signs assign right of way.
Collision Angles at Intersections
The closer a collision is to head on, the more serious the consequences for those involved. Displaced left turns, jug-handle loops, roundabouts, quadrant intersections and other intersection designs all impact the angle at which road users meet each other and reassign right of way.
Safe System Designs for Road Intersections
More Active Transportation means More Types of Road Users at Intersections
As part of the Federal Highway Administration and national effort to lower road fatalities, DOTs are encouraging active transportation alternatives to reduce cars on the road. Fewer people in vehicles also means more pedestrians at crossings, cyclists and scooters in the bike lane and public transit users. All of whom are meeting at intersections. The Safe System approach can be used to incorporate intersection features that take possible human error into account. This proactively reduces the risk of intersection crashes that may potentially lead to death and serious injury.
Beyond the Roundabout, Look at the Driving Data to Understand the Context
For example, a 3.5-mile radius around an intersection is considered the bikeable or walkable distance around it. In a Safe System, road experts consider the immediate surroundings. Are there schools, retirement homes, parks or commercial activities nearby? Who needs to get to what destination, and how are they going to get there?
Analyzing driver behavior highlights where drivers are suddenly and atypically changing their behavior in reaction to their surroundings. Understanding the reasons for this change helps to determine what about the context at a particular traffic light or controlled intersection, say, needs to be managed.
Reduce Accidents at Intersections through Road Safety Measures
Road experts can then apply strategies such as minimizing and modifying conflict points, reducing vehicle speed, improving visibility and providing sufficient space and protection for vulnerable road users. Driving behavior analysis can make the difference between a fatality, serious injury, minor injury, near miss – and no incident at all.
How Driving Data can Support Proactive Road Safety at Signalized and Unsignalized Intersections
Challenge: Provide all road users with all the information they need in a format that can be read, understood and applied in sufficient time to react. Ensure all road users see each other.
Who: Motor vehicles, pedestrians, cyclists, public transit – all of whom have different needs.
- Lights: Sequence each type of road user’s passage through the intersection.
- Minor road stops: Stop signs tend to be placed at the minor approaches, making it harder for pedestrians and cyclists to cross. They have to wait for a gap in traffic.
- All-way stops: Stop signs are placed at all approaches, which means that vehicle speeds are typically lower. Crossing opportunities for pedestrians and cyclists are more frequent.
Red-light running: The FHWA states that half of all people killed are not violators, but passengers, other motorists, pedestrians and bikes.
Stop signs aren’t heeded: By either drivers or other road users.
Driving behavior analysis: Analyzing and understanding driver behavior can reveal problems inherent to specific intersections and their immediate vicinity. Sudden braking, sudden acceleration or speeding indicates that drivers are reacting to a problem on the road. The severity of this type of behavior – its intensity and frequency – shows just how dangerous one particular intersection may be, or indeed, several. Repeated instances of suspected collisions are a symptom of a potential crash happening. Studying specific driver behaviors, at which intersections they cluster and under what conditions therefore provides actionable insights into how to modify each and avoid new intersection crashes.
MICHELIN DDi’s Expertise in Safer Roads at Intersections
Preventive road safety at intersections requires new technology that can help detect if and when they are risky. MICHELIN DDi’s driving data expertise can help.
MICHELIN DDi, Your Partner for Preventive Road Safety
Combining our expertise in data science and driving behavior, we create solutions that help you detect, locate and assess where high speed and other road safety issues are happening in your transportation system.
Intersections are priority areas for proactive road safety. Our driving data captures all driving events. After aggregating and contextualizing them, our data scientists apply algorithms and machine learning, transforming them into insights for road safety. Compatible with any GIS, you read the driving data like a heat map, seeing at which intersections events cluster and under what conditions, and how severe they are.
There are three levels of service to help you understand road safety at intersections:
- Locate and count how often events happen
- Assess and rank near miss hot spots
- Identify the probability of a crash occurring.
Driving events act as your key performance indicators. They are facts on which to base your decisions. You evaluate and prioritize road safety measures to address risky road intersections – before car crashes happen. After implementing changes, driving data KPIs again show the impact of the changes made.
Partner with MICHELIN DDi to accelerate your road safety strategy. Reach your Vision Zero goals with our mobility insights.
Contact MICHELIN DDi to locate risky road intersections in your transportation system.