Sun Glare Risk in Highways

Deslumbramiento por sol en carretera

Sun Glare Risk  in Highways

Sometimes, when we are driving in a highway and depending on the orientation we are affected by sun glare. This glare can make it much harder to see the road ahead and potential hazards creating an added risk to drivers.

RoadSolarInspector Application developed for mobile devices allows to analyze and to study highways in which this phenomenon is present throughout the year.

The application integrates a calculation engine that computes the solar positions for every hour of the year in relation with the roadway alignment (geographic coordinates). Finally, the application visualizes in a map (with colors) the zones with sun glare risk.

RoadSolarInspector allows to analyze in every point and for every day of the year the evolution of the Sun position (azimuth and altitude) and the angle of solar ray.

Who must download the application?

This new application is recommended for anyone who wants to know about sun glare when we are driving and especially it is directed to:

- Road Technical designers (engineers)

- Managers of road infrastructures

- Road Safety Auditors

Program Installation

The application uses Google Maps. You can download from official web Google Play Store.

RoadSolarInspector App. can be requested free of charge by completing this form.


Application Description

You must install the application. Then you will see a new icon in the smartphone screen.  You must touch this icon and then the application begins.

Menu inicio app

App Start Menu

You can choose three options: Captura desde GPS (record GPS coordinates), Captura desde mapa (record Maps coordinates) and Manual de uso (User’s Manual).

With the option “Captura desde GPS” you can record the road GPS coordinates using your smartphone.

Pantalla GPS

Record GPS Coordinates

Select ‘Activar’ button to start recording and ‘Desactivar’ button to finish. With ‘Escribir Datos’ button the information is saved in the disk (path/RoadSolarInspector).  With ‘Cargar datos’ button you can see the GPS points had been registered in a map (geographycal coordinates).

Ejemplo trazado en GPS

GPS Alignment

Recording Map Coordinate

With “Captura desde mapa” button you can record map coordinate. In order to get the point you must clicking in the map.

Ejemplo rotonda

Roundabout example

Simply swipe down the screen with two fingers and slide them. You can change the angle of visualization of the map.

‘Procesar Soleamiento’ button calculates sun glare risk with the points selected.

Procesado del soleamiento

Sun Glare Analysis

When is sun glare risk for drivers?

For each point P RoadSolarInspector takes the Coordinates System X’Y’Z’ (West – South – Zenith) (see figure) and Solar Azimuth angles and the Solar Vector (PS)

Ejes de referencia

Reference Axes

Azimuth ( ψ ): Solar Azimuth angle (PS) on the horizontal plane and south direction. Altitude of the Sun (α): Angle that the solar ray form with the horizontal plane

RoadSolarInspector calculate sun glare when the angle (in plant) formed by the vector PS (between our position ‘ point P ‘ and the Sun ‘ Point S ‘), and the road represented by the vector PP ‘ (P ‘ is the following point of the tour), is lower than a threshold (‘Angulo de Soleamiento’ Sun Glare Angle).

This threshold is divided in 3 levels of risk:

Zonas de riesgo

Risk Area

The Sun Glare Angle is the total angle in the Zone 3 (green). Zone 2 (yellow) is 2/3 that the Zone 3 and Zone 1 (red) is 1/3. You can change the Sun Glare Angle (15º) in ‘Angulo Soleamiento’ Menu.

Menú zonas de riesgo

Risk Area Menu




All the application options are in the Menu.

Tipo de Vista (View)

You can choose: Normal (normal), Híbrida (hybrid), Satélite (satellite) y Terreno (Maps).

Zona de Riesgo (Risk Area)

There are 3 risk areas: Zone 3 is the sun glare angle, Zone 2 is 2/3 that this angle and Zone 1 is 1/3.

The red color means more Sun glare hours and the green color less. 

Mapa de color (riesgos)

Color Maps (Risks)

You can see the sun glare hours in the year (and percentage) if you click on each point .

Información de punto

Point information

- Mostrar Coordenadas y Distancia entre Puntos (Show Coordinates and Distance between points)

You can see the geographic coordinates ( Latitude and Longitude) in each point or the distance between two consecutive points.

Coordenadas geográficas

Geographic Coordinates

Distancia entre puntos

Distance between points


Select a point and you can see these graphics: beta angle, azimuth (‘Acimut Solar’), Solar Altitude (‘Altura Solar’) and Solar Vector (‘Vector Solar’).  

Información por punto y día del año

Point and Day of the Year Information

Beta Angle is the angle (in plant) formed by the vector PS (between our position ‘ point P ‘ and the Sun ‘ Point S ‘), and the road represented by the vector PP ‘ (P ‘ is the following point of the tour)

Ángulo beta, acimut y altura solar

Beta Angle, azimuth and Solar Altitude

The Solar Vector is the Sun position (X’ West – Y’ South). The Graphic represents this vector in different hours of the day.

Vector solar

Solar Vector

- Exportar Ruta / Importar Ruta (Export/Import)

The application allows to save the road registered for his later use. You must select ‘Exportar’ button to save it and ‘Importar’ button to read the information again.

- Capturar Pantalla (Screen Capture)

You can do Screen Captures of anyone of the options that the application allows. The images will be saved in the folder ‘RoadSolarInspector/Capture’. You can save the graphs in the folder RoadSolarInspector/Graficas’.

- Mostrar/Ocultar Puntos (Show / Hide Points)

You can hide the points to see the risk map better.

Move a Point

You can Press to select a point and then slide your finger to move it. 


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