Determining Speed (CSR 102)

This course is intended to discuss the mathematical equations used to determine the safe speed for a given road configuration and provide insight to give an investigator the ability to determine the speed of a vehicle that leaves a skid mark or skids to a stop across multiple surfaces.

This course consists of four (4) video lessons, including an assessment at the conclusion of each segment.

Credit: 4 hrs.

Determining a Safe Speed

Lesson Purpose: This lesson is intended to discuss how basic mathematics allows an investigation to determine the safe speed for a given roadway configuration. The determination of safe speed and the mathematical formulas for determining the safe speed are discussed and practiced.

Training Objectives: At the end of this lesson, the student will be able to achieve the following objectives in accordance with the information received in class:

1. Demonstrate knowledge of the basic principles of mathematics and physics as they relate to crash scene reconstruction.
2. Understand a safe stopping distance for a given collision scenario and how to obtain the necessary variables.
3. Understand how to calculate the safe speed for a vehicle involved in a collision to determine if the vehicle speed contributed to the collision.

Video Length: 00:12:56

Determining Basic Speed

Lesson Purpose: This lesson is intended to discuss how basic mathematics allows an investigator to determine the speed of a vehicle that skids to a complete stop. The determination of basic speed and the formulas for determining the basic speed are discussed.

Training Objectives: At the end of this lesson, the student will be able to achieve the following objectives in accordance with the information received in class:

1. Understand how to determine a vehicle’s Center-of Mass in collision reconstruction.
2. Calculate a basic speed for a vehicle that skids to a complete stop.
3. Understand the difference between units of feet per second and miles per hour in a given scenario.
4. Understand how to determine Friction Values by using the Basic Motion Equation when investigating a collision.

Video Length: 00:13:44

Determining Combined Speed

Lesson Purpose: This lesson is intended to discuss how basic mathematics allows an investigator to determine the combined speed for a vehicle that skids to a complete stop across multiple surfaces. The mathematical formulas for combined speed are also discussed.

Training Objectives: At the end of this lesson, the student will be able to achieve the following objectives in accordance with the information received in class:

1. Understanding the concept of combined speed for a vehicle that skids to a complete stop over multiple surfaces.
2. Demonstrate an understanding of how the Kinetic Energy Equation can help to determine combined speed.
3. Understand how the origin of calculation can help to determine the deceleration for a vehicle to come to a complete stop.

Video Length: 00:12:49

Critical Speed Scuff Mark Analysis

Lesson Purpose: This lesson is intended to discuss how basic mathematics allows an investigator to determine the critical speed of a scuff mark. The critical speed formula is also discussed and practiced.

Training Objectives: At the end of this lesson, the student will be able to achieve the following objectives in accordance with the information received in class:

1. Explain the terms: Sideslip and Heading Angle
2. Demonstrate an understanding of the Concept of Sideslip as it applies to collision reconstruction.
3. Demonstrate an understanding of basic methods for obtaining critical speed scuff marks.
4. Demonstrate an understanding to determine the minimum vehicle speed at the initiation of a mark in a collision investigation.
5. Understand how to calculate the critical speed of a curve on the roadway.

Video Length: 00:12:51