Which environmental change is most likely to reduce speeding on residential streets?

• A. Increasing stop signs on all streets
• B. Raising fines for speeding
• C. Painting more crosswalks
• D. Installing a speed hump on a residential street

Answer: (D)

Environmental changes that slow traffic focus on making high speeds uncomfortable or impractical for drivers. A speed hump achieves this by creating a physical obstacle across the road that forces drivers to slow down to pass smoothly. Because it’s a permanent feature, the reduction in speed happens consistently, regardless of whether drivers are paying attention to signs or whether enforcement is present. This kind of traffic-calming measure lowers both average speeds and speed variability, which in turn reduces the likelihood and severity of crashes on residential streets.

Other options rely more on warnings, signals, or penalties. Adding more stop signs interrupts flow but can lead to drivers accelerating between them or simply treat the signs as a goal to crest, not a brake. Painting crosswalks improves pedestrian visibility but doesn’t reliably slow drivers. Raising fines depends on enforcement and may not reduce speeds if officers aren’t consistently present. In contrast, a speed hump directly changes the driving environment to promote safer speeds.