Background: There is growing urgency for higher quality evidence to inform policy. This study developed geographic information system spatial measures based on land use and transport policies currently used in selected Australian states to assess which, if any, of these measures were associated with walking for transport. Methods: Overall, 6901 participants from 570 neighborhoods in Brisbane, Australia, were included. Participants reported their minutes of walking for transport in the previous week. After a review of state-level land use and transport policies relevant to walking for transport across Australia, 7 geographic information system measures were developed and tested based on 9 relevant policies. Data were analyzed using multilevel multinomial logistic regression. Results: Greater levels of walking for transport were associated with more highly connected street networks, the presence of public transport stops, and having at least 2 public transport services per hour. Conversely, neighborhoods with shorter cul-de-sac lengths had lower levels of walking for transport. There was no evidence of associations between walking for transport and street block lengths less than 240 m or traffic volumes. Conclusions: These findings highlight the need for urban design and transport policies developed by governments to be assessed for their impact on transport-related physical activity.