Sunglare … Where?


James R. Schmidt, Jr., BSME, Sr. Collision Reconstruction Engineer ::::
This is one of the times of year where motorists are regularly encountering sun glare. The sun is low in the eastern sky during morning rush hour. The sun is low in the western sky during evening rush hour.
Take this morning, for example. I was on my ride to work, and voila … sun glare! Continue reading “Sunglare … Where?”

Speed From Video… Another Masterpiece


James R. Schmidt, Jr., BSME, Sr., Collision Reconstruction Engineer ::::
As you probably know by now, DJS can analyze dash cam and still-camera surveillance videos to quantify vehicle speed (and other parameters, if necessary). Of course, the ability to evaluate is dependent on the quality of the video, as well as the presence of fixed objects or other points of reference visible in the video for use in determining distance travelled over time (i.e. speed is distance divided by time). DJS has performed this type of analysis countless times. Quite possibly, DJS has worked with you on a case in which such an analysis was performed, or you may have read some of our other prior articles wherein this topic has been discussed at length.
With a video in hand (a dash cam video in this instance): Continue reading “Speed From Video… Another Masterpiece”

Mobile Digital Billboards!

Digital Billboard

James R. Schmidt, Jr., BSME, Sr. Collision Reconstruction Engineer ::::

I recently saw my first mobile digital billboard truck while on the road. It was very eye-catching, and somewhat distracting, to say the least. The reflection of the digital display off the wet roadway contributed to the distraction. If you happen to see a mobile digital billboard truck while driving, be sure to keep your eyes on the road as best you can!

Continue reading “Mobile Digital Billboards!”

Don’t Underestimate the Importance and Power of Event Data

Event Data

James R. Schmidt, Jr., BSME, Sr. Collision Reconstruction Engineer ::::
The capability of recording event data when a crash occurs is becoming more prevalent in vehicles on the road today.
Once a crash occurs, as part of the investigation process, event data should be collected from all vehicles involved that have such recording capability.
Having been collected, the data can be reviewed and analyzed by a collision reconstruction engineer, as part of his or her analysis process. And yes, you do need to be trained in order to properly interpret, analyze, and incorporate this data into a collision reconstruction.
Oftentimes, the client is interested in knowing such things as how fast a vehicle was traveling, and whether the operator applied the brakes before impact.
Take, for example, a collision involving a Ford Ranger pickup running into the rear of a motor coach. The crash took place pre-dawn, as the motor coach was starting from a stop when the traffic signal turned green. Continue reading “Don’t Underestimate the Importance and Power of Event Data”

Sun Glare… What a difference a day makes!

James R. Schmidt, Jr., BSME, Sr. Collision Reconstruction Engineer ::::
Sun glare occurs when the sun is positioned low in the sky ahead of the direction of travel on a given roadway. It can occur in the time periods following sunrise or preceding sunset. And, it’s just what it sounds like … it’s when the sun is right in your face, thereby complicating the task of driving!

Continue reading “Sun Glare… What a difference a day makes!”

Amish Horse and Buggy

James R. Schmidt, Jr., BSME, Sr. Collision Reconstruction Engineer ::::
During my travels this past holiday season, I encountered a single-horse Amish buggy heading eastbound on State Route 372 between Buck and Quarryville, in Lancaster County, PA. These buggies are a familiar sight in this area of Lancaster County. A couple of years ago during the height of summer, we counted over 30 buggies during our one-way travel along this route!
As a collision reconstruction engineer, I’m always interested in how fast vehicles are travelling, among other parameters. So, I’d like to take this opportunity to report a “fun fact”. Once again, using my Garmin dash cam and the GPS speed displayed thereon (note that I forgot to turn off the daylight savings time setting, as it’s dark outside by nearly 6 PM!), I am reporting the average speed of a typical single-horse Amish buggy on generally flat, level ground to be on the order of 6 mph. Specifically, the dash cam reported my speed as 6 mph as I followed the buggy for a short distance, while waiting for opposing traffic to pass and then ultimately for the buggy to make its left turn. Also, by measuring the distance between the two positions shown below on an aerial photograph (157 feet) and dividing by the time to travel this distance (18 seconds), I have independently confirmed my speed, and hence the buggy speed, to have been 6 mph on average.


While a “fun fact” to those reading, this point of reference for a horse and buggy speed could come into play in a future evaluation, as DJS Associates has been retained on several Amish buggy crashes over the years.
James R. Schmidt, Jr., is a Sr. Collision Reconstruction Engineer with DJS Associates and can be reached via email at or via phone at 215-659-2010.

What are Those “Stripes” on the Roadway?

James R. Schmidt, Jr., BSME, Sr. Collision Reconstruction Engineer ::::
We’ve all seen them during the winter season … white stripes running along the length of the roadway.

stripes on roadway

stripes on roadway

stripes on roadway

But what are they? Those stripes are dried lines of salt brine applied by PennDOT, or local municipalities, in advance of a frozen precipitation event. According to literature on the PennDOT website:
Continue reading “What are Those “Stripes” on the Roadway?”

‘Tis the Season…

car accident/collision

James R. Schmidt, Jr., Sr. Collision Reconstruction Engineer ::::
It’s the first snow of the season, and it looks beautiful, right? Not when you’re involved in a crash first thing on a wet/snowy morning!
car accident/collision
When it snows, and the roadway is wet, slushy, snow-covered, or icy, know that that the laws of physics dictate that it will take longer to stop. Reduce your speed. Leave extra room between your vehicle and the vehicle in front of you. Take turns more slowly. And, regardless of the weather, never turn left until it’s clear to do so. Even if the traffic light is changing from green to yellow to red, you must wait to make sure opposing traffic is stopping before proceeding through the intersection to complete your left turn!
Continue reading “‘Tis the Season…”

One Dash Cam Video and a Feisty Engineer


James R. Schmidt, Jr., Sr. Collision Reconstruction Engineer ::::
I love dash cam videos! Who am I kidding… I love all videos equally, surveillance included! Especially when they capture a crash!
Driving home from dinner on a Friday night, I encounter an accident scene with emergency vehicles present.
I don’t like to rubberneck, and as it turns out, I don’t need to… I have a dash cam! Me being a collision reconstruction engineer, I took the first opportunity I could to review the video afterward! Here’s what I have concluded:
A pickup truck rear-ended the white SUV.
Continue reading “One Dash Cam Video and a Feisty Engineer”