Adaptive Street Lamp Color Control for Pedestrian Visibility

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Solution Overview

Problem

Pedestrians are at higher risk of severe accidents at night due to reduced visibility and glare from increasing car headlights, necessitating improved pedestrian visibility and driver awareness near pedestrian crossings and bus stops.

Innovation Solution

A street light with a sensor system that dynamically adjusts spectral properties and light frequency based on pedestrian presence, using UV light to make clothing fluoresce, flashing, or altering color to enhance visibility and alert drivers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If the light intensity of car headlights is increased, then the visibility for drivers is improved, but glare for oncoming vehicles increases and contrast is reduced

Engineering Contradiction:
ImprovevisibilityVSAvoidglare
Core Design Contradiction:
Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The street light changes its spectral color from warm white to cool white tone when a person is detected, making the pedestrian crossing appear in dazzlingly bright light. This color change increases the driver's attention and makes pedestrians more noticeable without requiring excessive intensity that would cause glare.

Inventive Principle:
Principle #32Color changes

Solution Approach 2:

The control device increases the ultraviolet component of the light emitted by the street lamp when a person is detected. The ultraviolet light produces fluorescent light on the clothing of the detected persons, making them particularly easy to see at night for the driver of an approaching vehicle.

Inventive Principle:
Principle #35Parameter changes

2Illumination intensity

If permanent lighting is provided at pedestrian crossings, then visibility is improved, but drivers may become accustomed to the light pattern and awareness is reduced

Engineering Contradiction:
ImprovevisibilityVSAvoiddriver awareness
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The street light is controlled to change its spectral color or light frequency only when a person is detected by the sensor. This periodic activation of light changes prevents drivers from becoming accustomed to specific light patterns that are permanently present at that location, while still providing adequate illumination when needed.

Inventive Principle:
Principle #19Periodic action

3Reliability

If the light spectrum is modified to enhance pedestrian visibility, then driver awareness is improved, but energy consumption increases

Engineering Contradiction:
Improvedriver awarenessVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The street light dynamically adjusts its spectral properties and light frequency based on real-time detection of pedestrians. The control device increases the ultraviolet component and changes color only when a person is detected, rather than maintaining modified spectrum continuously, thus reducing energy consumption while maintaining driver awareness when needed.

Inventive Principle:
Principle #15Dynamics

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enhances pedestrian visibility and driver awareness by making pedestrians more noticeable and alerting drivers to potential hazards, reducing accidents through dynamic lighting adjustments.

Implementation Method 1

The ultraviolet light produces fluorescent light on the clothing of the detected persons

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Data Source

PatentEP3770489B1Adaptive street lamp with person detector
Publication Date: 2026.04.01 SITECO GMBH
  • EP3770489B1 patent drawingFigure 1

AI summary

Street light (2) for placement on the road near a place with increased pedestrian traffic, e.g. a pedestrian crossing or a bus stop, wherein the street light (2) is connected to a sensor (4) which is configured to detect the presence and/or movement of persons, and the street light (2) has a control device which is configured to change a spectral color and/or a luminous frequency of a light (6) emitted by the street light when a person is detected.