Noise Levels
Road, rail, and environmental noise assessments
High Rail Noise
Significant train noise
High rail noise is the top band Propbar assigns from the strategic noise maps. It marks modelled train noise over 70 dB Lden. The Lden figure is a year-round average that counts evening and night trains more heavily than daytime ones. All four UK nations map strategic noise, each through its own government body.
High Road Noise
Significant traffic noise
High road noise is the top band on the strategic noise maps: modelled traffic noise over 75 dB Lden. Lden combines day, evening and night traffic noise into one annual figure, penalising the later hours. The maps are remade in rounds roughly every five years. Every UK nation produces this mapping, through a different body.
Low Rail Noise
Minimal train noise
Low rail noise is the bottom band on the strategic noise maps: modelled train noise under 60 dB Lden. Lden is an annual average of day, evening and night noise, with evening and night weighted higher. Each UK nation publishes its own strategic noise mapping.
Low Road Noise
Minimal traffic noise
Low road noise is the lowest band the report derives from strategic noise maps. The figure captures road traffic only, not railways or aircraft. Lden sums a full year of that traffic noise into one figure, weighted towards evening and night. The four UK nations each publish their own version of these maps.
Medium Rail Noise
Moderate train noise
Medium rail noise covers modelled train noise of 60 to 70 dB Lden on the strategic noise maps. Lden averages a year of train noise across day, evening and night, penalising the later hours. Strategic noise mapping is devolved, and each UK nation runs its own.
Medium Road Noise
Moderate traffic noise
Medium road noise covers modelled traffic noise of 65 to 75 dB Lden on the strategic noise maps. Lden is a 24-hour indicator averaged over a year, with evening and night hours carrying extra weight. The maps model a grid of the wider area, not individual front doors. Responsibility for the mapping is devolved to each UK nation.