Photometric calculations are carried out first, using Lighting Reality and DIALux, to establish the lux levels, uniformity, and glare control required for the scheme’s classification. Only once the calculation is correct do we develop the column layout, spacing, and lighting plan in CAD and BIM — coordinated to the scheme’s road geometry and classification requirements. Calculating before modelling means the drawing reflects a design that’s already been verified, not one that’s checked after the fact.