How does higher urban density influence transportation mode share and emissions?

• A. It has no impact on mode share.
• B. It supports more walking, biking, and transit, reducing emissions.
• C. It always increases vehicle miles traveled.
• D. It leads to higher emissions regardless of infrastructure.

Answer: (B)

Higher urban density puts people, housing, jobs, and services closer together, which makes walking, biking, and transit more practical and appealing. When destinations cluster along compact, well-connected streets, it’s easier for people to reach what they need without driving, and transit becomes more efficient and capable of serving more riders. As more trips are made by walking, cycling, or riding transit, fewer car trips occur, and those car trips are often shorter, both of which reduce transportation emissions. Of course, density works best when it’s paired with good infrastructure—safe bike networks, walkable streets, mixed land use, and a reliable transit system—but the overall effect tends to shift mode share toward lower-emission options, lowering emissions overall.