This study examined the granulometry of non-colloidal particulate matter (PM) from four urban transportation land use catchments (source areas) in Baton Rouge, Little Rock, North Little Rock, and New Orleans. Particle gradations ranging from 1 to greater than 10,000 μm were separated into dissolved (less than 1 μm), suspended (1–25 μm), settleable (25–75 μm), and sediment (75–4750 μm) fractions. In Baton Rouge, the primary site, results indicate a suspended mass-based d 50m of 10.8, 5.0 μm [mean ( $$\bar x$$ ), standard deviation (s)], a particle density (ρ s) of 2.40, 0.19 g/cm3 based on 12 events with complete runoff volume capture. On an event-basis, the suspended fraction ranged from 5–25% of the entire gradation mass and correlated to turbidity. The Baton Rouge d 50m excluding grit-size material from all events was 356, 69 μm as compared to 421, 219 μm for accumulated PM including grit from all sites. Size gradations were successfully modeled with a gamma distribution. Particle density generally varied from 2.1 to 2.6 g/cm3 across gradations. While specific surface area generally increased with decreasing particle size, over 50% of total surface area was associated with gradations greater than 250 μm. The point of zero charge (pzc-pH) ranges from 7.5 to 9 for settleable and sediment fractions. Results from these sites support published results for fully captured rainfall–runoff events at a Cincinnati site of the same land use, and provide properties/indices for monitoring, regulatory guidance, treatability studies, source control, and design of in situ unit operations targeting particle separation mechanisms.