Roadway Safety Analysis

Crash Reconstruction

Truck Crash Reconstruction

Mechanical Failure Analysis

Truck Safety & Compliance

Brake Failure Analysis

Air Brake Failure Analysis

Truck Underride Collisions

Roadway Safety

Auto Event Data Recorders

Truck Event Data Recorders

Forensic Mapping

Computer Animation

Collision Repair Defects

Expert Testimony

Despite exceptional progress towards reducing fatal accidents, roadway defects such as faulty guardrails, hydroplaning sections, pavement edge drop offs, hazardous railroad crossings, and poorly signed construction zones persist in the US.

John C. Glennon, Chartered provides expert analysis of roadway safety and roadway defects. We apply standards of the industry to evaluate roadway sites as to their proper geometric design and maintenance and/or the need for remedial traffic control devices. A brief description of the key topics we address are listed below. To link to a roadway safety expert, click here.

Roadside Safety
The Forgiving Roadside Concept, Clear Zone Standards, Roadside and Median Barrier Design, Bridge Rails, Crash Cushions, Embankment Slopes, Breakaway Signs, Light Poles, And Utility Poles. Paper/Determining, Guardrail Length of Need. References.

Roadway Sight Distance
Stopping Sight Distance, Intersection Sight Distance, Passing Sight Distance, Railroad Grade Crossing Sight Distance, American Association of State Highway and Transportation Official Standards. Paper/What's Wrong with Applying the New AASHTO Opposing Left-Turn Intersection Sight Distance Standard to Existing Roadways? References.

Slippery Pavements And Hydroplaning Areas

Slippery Pavements And Hydroplaning
Pavement Skid Resistance, Pavement Texture, Insufficient Pavement Cross Slope, Sag Vertical Curves, Alignment Transitions, Blocked Culverts, Wheel Ruts, Pavement Depressions, Bleeding Asphalt. Paper/Hydroplaning The Trouble with Highway Cross Slope.

Pavement Edge Drop-Offs
Maintenance Standards, Construction Zone Standards, Tolerable Heights, Research Results Relating Speed, Tire Scrubbing, Tires, Vehicles, Etc. A Primer on Roadway Pavement Edge Drop Offs. References.

Traffic Control Devices
Signs, Signals, and Markings, Manual on Uniform Traffic Control Devices, Traffic Control Device Handbook, Roadway Curve Signing. Paper/Thoughts on a New Approach to Signing Roadway Curves. References.

Accommodating Driver Information Needs
Warning Signs, Signals, Markings, and Road Designs that Provide Information Consistent with Driver Expectancy through Positive Guidance, which Minimize Driver Distractions, Confusion, and Work Load. References.

Construction Zone Operations
Traffic Control Plans, Positive Guidance, Speed Zoning, Barricades, Merging Tapers, Lane Closures, Work Space, Buffer Space, Flagging, Detours, Unencumbered Roadsides, Road Closures, One-Way Traffic Control, Mobile Operations, Advance Warning Arrow Panels, Changable Message Signs, Training. Paper/Application of Traffic Safety Principles in Construction Work Zones — The Dilemma. References.

Roadway Maintenance
Pothole Repair, Shoulder Drop-Offs, Wheel Rutting, Snow and Ice Control, Washboard, Dust Control, Asphalt Flushing, Micro Skid Surfacing, Debris on Pavement. References.

Railroad Crossings
Vehicle-Train Conflict Circumstances, Driver Information Needs, Flashing Signals, Automatic Gates, Sight Triangles, Nearby Intersections, Acute Angle Crossings, Steep Crossing Grade, Rough Crossing Surface, Signal Pre-Emption. Paper/Railroad Defense Definition of Extra-Hazardous Grade Crossings / A Rebuttal.