Indicolors of Ironsport efficiency in 37 global cities: V.A.: Institute for Science and Technology Policy. A Risk-Based Method for Modeling Traffic Fatalities. Risk Ar 5 Dumbaugh and Roe. They found that area crash rates decline significantly with increasing bus stop density, percentage of public transport-km travelled relative to total vehide-kms travelled, and walking, biking, and public transport-commute mode share. Their modelling indicates that a strategic transport plan that encourages use of alternative modes tends to reduce total, severe, and property damage collisions.