3 Common Crash Scenarios That Call for a Traffic Engineering Expert
Crashes are a tragic but unfortunately common occurrence on our roadways, often leaving drivers, pedestrians, and families searching for answers. In many of these situations—particularly when legal, insurance, or safety questions arise—an experienced traffic engineering expert can play a critical role in uncovering what happened and why.
At Greenlight Traffic Engineering, we bring over 50 years of combined experience to every case we handle. We’re frequently called upon as expert witnesses to analyze crash sites, traffic patterns, road designs, and control systems. While each crash is unique, certain types of scenarios regularly come up in our work. Below are three of the most common types of crash investigations we’re asked to evaluate—and what we typically look for in each case.
1. Work Zone Crashes
Construction zones are temporary disruptions to normal traffic flow—and they can be confusing and dangerous if not designed and maintained correctly. These areas often include lane shifts, detours, temporary signs, reduced speed zones, cones, barrels, or portable traffic signals. While necessary for road maintenance and improvements, construction zones are also a frequent site of crashes.
When an incident occurs in a work zone, our team is typically brought in to answer key questions like:
- Were the temporary signs and barriers properly placed?
- Was the work zone in compliance with federal and state standards, such as the Manual on Uniform Traffic Control Devices (MUTCD)?
- Did the layout of the zone contribute to the crash—or could the crash have been prevented with a better design?
Our analysis often includes reviewing the setup of traffic control devices, comparing the zone’s configuration to the approved traffic control plans, and examining the timeline of any changes made. We also consider driver expectations, visibility, and how effectively the setup guided vehicles through the area.
Crashes in construction zones often result in serious injuries or fatalities. Because of this, the stakes are high when determining responsibility—and a detailed traffic engineering analysis can provide the clarity needed for legal proceedings or future safety improvements.
2. Crashes at Signalized Intersections
Signalized intersections are another common location for traffic collisions. These are particularly risky environments because they often involve multiple lanes of movement, opposing traffic flows, left-turn conflicts, and pedestrian crossings. When drivers misunderstand signal phases or when the timing of lights doesn't support safe traffic flow, crashes can quickly occur.
The most common types of collisions we evaluate at these intersections include:
- Left-turn crashes
- Pedestrian or cyclist strikes
- Rear-end or T-bone collisions due to misinterpreted signals
As traffic experts, we look closely at a variety of factors:
- Signal timing and phasing – Were the signals providing enough clearance time for vehicles to safely pass through the intersection?
- Signal visibility – Were the traffic lights clearly visible, especially at night or during poor weather?
- Pedestrian signals and crosswalks – Were pedestrian signals functioning properly and giving walkers enough time to cross?
- Intersection design – Were there any sight obstructions, such as trees or signage, affecting a driver's ability to see other users?
We use simulation tools and historical traffic data to assess whether the intersection’s design, timing, and control systems played a role in the crash. These technical insights often prove essential in determining liability and proposing changes to prevent future incidents.
3. Pedestrian and Bicycle Crashes
With increasing efforts to promote walkability and cycling in cities and towns, pedestrian and bicycle safety has become a major focus in traffic engineering. Unfortunately, these road users remain some of the most vulnerable—and when crashes happen, the consequences can be devastating.
Our investigations into pedestrian and bicycle crashes tend to center on a few key issues:
- Crosswalk design and placement – Was the crossing clearly marked and located at a safe and visible point on the roadway?
- Signage and lighting – Were there appropriate warning signs, pavement markings, or flashing beacons to alert drivers? Was the area well-lit at night?
- Speed control and sight distance – Were drivers given enough time and distance to react to a pedestrian or cyclist in the roadway?
In many cases, we find that the design of the street may not have fully accounted for the needs of non-motorized users. For example, a crosswalk may be present but placed too far from natural pedestrian paths, or traffic speeds may be too high in areas with heavy foot traffic.
We also consider human factors, such as typical driver behavior, pedestrian behavior, and environmental conditions at the time of the crash. A thorough crash reconstruction that incorporates traffic engineering principles can reveal important insights that might otherwise be missed in a standard investigation.
Why Traffic Engineering Expertise Matters
Understanding the technical side of a crash goes far beyond reviewing police reports or eyewitness statements. Traffic engineers bring a unique and scientific lens to crash investigations, combining knowledge of roadway design, human behavior, traffic control devices, and safety standards.
At Greenlight Traffic Engineering, we specialize in complex crash analysis for attorneys, municipalities, insurance companies, and private organizations. Our role often involves:
- Serving as expert witnesses in litigation
- Conducting independent investigations and reconstructions
- Advising on roadway improvements and risk reduction
- Helping clients understand the root causes of collisions
By applying our technical expertise, we can provide objective, data-backed answers that are critical for both legal resolution and future safety enhancements.
Work With a Trusted Traffic Engineering Team
If you’re involved in a crash investigation—whether you're a legal professional, a municipality, or an insurance provider—it pays to have traffic engineering experts on your side. With decades of experience and a commitment to objective, detailed analysis, Greenlight Traffic Engineering is a trusted partner for evaluating complex traffic scenarios.
Whether you're dealing with a construction zone crash, a complicated signalized intersection, or a pedestrian incident with unclear contributing factors, our team is here to help you uncover the truth.
Contact Greenlight Traffic Engineering today to learn more about how we can support your case or project with our specialized expertise.
