Science of Hi Viz Safety apparel

Introduction

High visibility and retro-reflective materials are designed to improve visibility in low-light conditions, making them essential for safety applications such as pedestrian safety, worker visibility, and bike rider safety. This guide will provide an overview of the factors affecting the detection and recognition of pedestrians, workers, and bike riders, the problems associated with motorists' vision at night and under low-light conditions, and the characteristics of high-visibility fluorescent and retro-reflective materials.

Factors Affecting Detection and Recognition of Pedestrians, Workers, and Bike Riders

Low-light conditions can make it difficult to detect and recognize pedestrians, workers, and bike riders, increasing the risk of accidents. The following factors can affect visibility:

 Clothing color: Dark clothing can make it difficult for drivers to see pedestrians, workers, and bike riders at night. Light-colored clothing is more visible in low-light conditions.

   Contrast: The contrast between the clothing and the background can affect visibility. High-contrast clothing is more visible than low-contrast clothing.

   Movement: Pedestrians, workers, and bike riders who are moving are more visible than those who are stationary.

   Lighting: Adequate lighting can improve visibility of pedestrians, workers, and bike riders.

Problems Associated with Motorists' Vision at Night and Under Low-Light Conditions

Motorists' vision can be impaired at night and under low-light conditions, making it difficult to see pedestrians, workers, and bike riders. The following problems can affect visibility:

   Glare: Glare from headlights, streetlights, and other sources can impair vision.

   Low light levels: Low light levels can make it difficult to see pedestrians, workers, and bike riders.

   Reduced peripheral vision: Peripheral vision is reduced in low-light conditions, making it more difficult to see pedestrians, workers, and bike riders.

Characteristics of High-Visibility Fluorescent and Retro-Reflective Materials

The following materials are commonly used in safety applications to increase visibility:

   High-visibility fluorescent materials: High-visibility fluorescent materials, such as neon colors, are highly visible in low-light conditions. They absorb light and emit it at a higher wavelength, making them more visible to the human eye.

   Retro-reflective materials: Retro-reflective materials are designed to reflect light back to its source at a high intensity, making them the most visible in low-light conditions. They use microbeads or prisms to reflect light back to the source.

The Three Types of In-Conspicuity That Affect Pedestrians and Bicyclists

As pedestrians and bicyclists share the road with vehicles, it's important to be aware of the potential risks that can arise from in-conspicuity. In-conspicuity refers to the state of being hard to see or invisible, which can lead to accidents and injuries. In this article, we'll discuss the three types of in-conspicuity that can affect pedestrians and bicyclists, and provide tips for avoiding collisions.

Invisible Object

An invisible object is something that is hard to see due to its color, size, or location. For example, a polar bear in a snowstorm or a pedestrian wearing dark clothes at night can be considered invisible objects. These objects are dangerous for pedestrians and bicyclists because they can suddenly appear in front of them, giving them little time to react.

To avoid collisions with invisible objects, pedestrians and bicyclists can wear reflective clothing or use lights at night. This can make them more visible to drivers and reduce the risk of accidents.

Obstructed Object

An obstructed object is something that is hidden or partially hidden by another object. For example, a pedestrian stepping off a curb in front of a bus can be considered an obstructed object. These objects are dangerous for pedestrians and bicyclists because they can be hidden from view until it's too late to avoid a collision.

To avoid collisions with obstructed objects, pedestrians and bicyclists can look both ways before crossing the road and use designated crosswalks. This can help them avoid hidden obstacles and reduce the risk of accidents.

Visible Object Not Seen

A visible object not seen is something that is visible but is not seen due to shadows, glare, or other factors. For example, older pedestrians wearing dark clothing in winter can be considered visible objects not seen. These objects are dangerous for pedestrians and bicyclists because they can be in plain sight but not easily seen.

To avoid collisions with visible objects not seen, pedestrians and bicyclists can wear bright or reflective clothing and be aware of shadows and glare. This can help them make themselves more visible to drivers and reduce the risk of accidents.

Conspicuity Devices

The searching eye is attracted to size, intensity, repetition, and movement. A device which incorporates one or more of these attributes will greatly speed up the detection-reaction process.

When choosing conspicuity devices, select items which will provide bright steady light, a flashing light or a moving light or reflection. A variety of materials and devices are available that can increase conspicuity to varying degrees, under varying conditions.

The surest way for bicyclists and pedestrians to improve conspicuity is through the use of fluorescent clothing in the daytime and retro-reflective materials at night. "Wear white at night" isn't enough!

Commonly available conspicuity devices to see how effective they are.

Contrast

Contrast is one factor that can increase conspicuity. A person wearing several contrasting colors or colors that stand out against the prevalent background color tends to be more conspicuous than a person wearing only one color or a color that blends in with its surroundings. Contrast is not as effective a conspicuity measure as use of fluorescent, reflective or retro reflective materials, but has historically been recommended as a basic safety measure that can be taken by anyone, at no cost.

Fluorescent Materials

Fluorescent materials reflect more light than they absorb. Common fluorescent colors are blaze orange, hot pink and day-glo green. These colors seem to amplify light and cause the wearer to stand out in a crowd. Fluorescent colors are excellent for increasing conspicuity in daytime and under low-light conditions but are nearly worthless at night, when they tend to appear to be black.

If a person doesn't want to wear an entire item of apparel out of fluorescent material, conspicuity can still be improved by attaching a strip of the material to a coat, around an arm, to bicycle handlebars or to a purse. Anything that will cause a scanning eye to detect something out of the ordinary will increase conspicuity.

Reflective material

Use of retro reflective materials is the most effective way to increase conspicuity at night or under low-light conditions. These materials are not conspicuous in daylight.

Retro reflective material is made using tiny glass beads which reflect light directly back toward its source, from a much wider angle than reflective material.

Traffic signs and pavement markings are retro reflective. Retro reflective materials can be incorporated into clothing, helmets, bike equipment, backpacks or attachable strips.

Retro reflective material can help create a visual "signature" pedestrians at night or under low-light conditions. As we mentioned earlier, the signature helps the motorist identify the "thing up ahead" as a pedestrian rather than a fence post, motorcycle or snowplow. If the time it takes the motorist to detect and recognize a pedestrian or bicyclist can be reduced, there is more time to react and to avoid a crash if necessary. best reflector.

Reflective material is most effective when lights are shining directly at it. As the lights' angle increases away from 90 degrees, the material becomes less effective. If lights are coming from an angle of more than about 3 degrees off a direct line in any direction from the object (bicyclist or pedestrian) the reflector's effectiveness is seriously reduced. Be sure either to use a large piece of reflective material to increase the area that can reflect light or use multiple reflective devices.

A few years ago, small reflective dots were a popular item marketed to increase pedestrian safety. While these dots did reflect light, they were very small and didn't communicate enough information to motorists to increase recognition time sufficiently. Motorists could see something up ahead, but couldn't recognize it quickly as a bicyclist or pedestrian. The best way to create a signature that can be easily recognized at night is to reflectorize the pedestrian's limbs --to create an outline.

Arms and legs have a distinctive motion when bicyclists and pedestrians are on the move. Movement is one of the cues the brain uses to direct its attention. A reflector that is moving will be seen much more quickly than one that is stationary. Reflectors on bikes or on pedestrians will be seen by motorists sooner if they are mounted or worn low and on a moving part. Low-beam headlights are aimed down and toward the right shoulder, enabling drivers to spot low reflectors first.

Lights -- Steady and Flashing

At night, lights can do more than any other device to increase conspicuity. They can be combined with clothing and equipment to create a distinctive and conspicuous image. They also light the way for the pedestrian, showing the path ahead.

A steadily burning red taillight is detected and recognized much sooner than even best reflector. Flashing lights are even better.

A flashing taillight combined with a headlight which silhouettes the rider, can greatly enhance safety. Other products such as leg lights and flashing LED lights, are also available. These can be carried, or attached to a limb. They are often combined with various types of reflectorized vests and attachable reflective or retro reflective pieces.

A shining flashlight swinging back and forth in front of a pedestrian, visible to on-coming traffic is very attention-getting. It alerts motorists to the fact that something is moving (and possibly human) up ahead and that rapid reaction may be needed.

Summary,

High visibility and retro-reflective materials are essential for safety applications in low-light conditions. By understanding the factors affecting the detection and recognition of pedestrians, workers, and bike riders, the problems associated with motorists' vision at night and under low-light conditions, and the characteristics of high-visibility fluorescent and retro-reflective materials, you can choose the right materials for your safety applications and help reduce accidents.

In-conspicuity can pose a serious risk to pedestrians and bicyclists, but there are ways to reduce the risk of accidents. By understanding the three types of in-conspicuity and taking precautions such as wearing reflective clothing, using lights at night, looking both ways before crossing, and being aware of shadows and glare, pedestrians and bicyclists can stay safe on the road. Let's all do our part to promote pedestrian and bicycle safety and prevent accidents.

Author- Walter Frankline Peter