Table of Contents

## What is a roadway drag factor?

Drag Factor is the deceleration coefficient for an entire vehicle. In this article, the drag factor, or coefficient of friction, basically measures the stickiness of a surface such as a roadway, a grassy knoll, a ditch, and the like.

**What causes skid marks on the road?**

On asphalt road surfaces, skid marks are usually the result of bituminous oils in the asphalt that are heated because of the friction of braking or accelerating and rise to the surface, leaving dark marks. Braking marks will vary depending on whether the car uses ABS or not. If not, there will be two lines.

**What is drag factor in accident reconstruction?**

Drag Factor (f) is a non-dimensional (no units) number used to represent the acceleration or deceleration of a vehicle. It is defined as the total force F(tot) required for a vehicle’s acceleration (or deceleration) in the direction of acceleration, divided by the vehicle’s weight.

### What is drag factor?

Drag factor is a measure of fan load. The Performance Monitor self-calibrates on the RowErg and SkiErg by recalculating the drag factor on every pull, and the BikeErg needs to be calibrated from time to time.

**What are the different types of skid marks?**

There are actually three different types of skid marks: acceleration, braking and yaw. Acceleration marks would be darkest at the beginning, where the car was stopped, because the friction eases as the tires transmit more of the power from the engine under speed.

**What are the three types of skid?**

There are actually three different types of skid marks: acceleration, braking and yaw.

## How do you tell how fast a car was going in an accident?

Measuring the length of skid marks is another way that investigators can determine how fast the vehicles were traveling. When the skid distance, the drag factor due to road surface friction, and the braking efficiency are determined, the minimum speed of a car as it started skidding can be found.

**How do you calculate drag factor?**

The drag coefficient Cd is equal to the drag D divided by the quantity: density r times half the velocity V squared times the reference area A. The drag coefficient then expresses the ratio of the drag force to the force produced by the dynamic pressure times the area.

**What is Concept 2 drag factor?**

Drag factor is a measure of fan load. The Performance Monitor self-calibrates on the RowErg and SkiErg by recalculating the drag factor on every pull, and the BikeErg needs to be calibrated from time to time. On all our ergs, you get a true measure of your effort regardless of the damper setting or changing conditions.

### What kind of skid marks are from too much speed?

Acceleration scuff marks appear when there is enough power supplied to the driving wheels that it causes one of them to spin on the pavement. The typical scenario that results in an acceleration scuff mark is a driver who “spins out” with excessive speed.

**How is the drag factor of a roadway determined?**

Various scientific instruments (for example, the VC-3000) determines the drag factor of a roadway surface. These devices began in the research field and the drag racing world and are purchased for about $1,500.

**How is the drag factor and coefficient of friction related?**

Drag Factor is the deceleration coefficient for an entire vehicle. The Coefficient of Friction is the deceleration coefficient for a sliding tire. The Drag Factor and Coefficient of Friction are the same, if and only if, all four tires of a motor vehicle are locked and sliding on a level surface.

## Why do accident investigators need to know the drag factor?

In this article, the drag factor, or coefficient of friction, basically measures the stickiness of a surface such as a roadway, a grassy knoll, a ditch, and the like. So why does an accident investigator need to know what the drag factor of a roadway surface is and how do they use it?

**How are skid marks used to determine drag factor?**

These skid marks are measured, and a drag factor is calculated. Various scientific instruments (for example, the VC-3000) determines the drag factor of a roadway surface. These devices began in the research field and the drag racing world and are purchased for about $1,500.