Diverse traffic noise profiles across road networks remain largely undifferentiated using standardised noise indicators. To address this issue, this work derives two supplementary noise indicators for road traffic noise. The first supplementary indicator differentiates the impacts of daytime and night-time noise exposure. The second supplementary indicator differentiates heavy vehicle noise from commuter traffic noise. Both indicators are expressed in terms of hourly contributions of light and heavy vehicle noise associated with standard traffic noise indicators. The Spearman’s rank correlation coefficient is used to evaluate the strength of the relationship between the standard and supplementary noise indicators. Using the supplementary noise indicators, spatial variability of light and heavy vehicle traffic composition across urban and rural parts of a state road network in Australia is presented. The findings add a useful spatial dimension to large scale road traffic noise impact studies to better inform epidemiology and noise management action plans.