New research: “Eighty-five percent solution: historical look at crowdsourcing speed limits and the question of safety”
By Brian D. Taylor and Yu Hong Hwang, June 30, 2020. The “85th percentile rule” has been used for decades to set speed limits in jurisdictions across the US. New research shows it originated earlier than most thought, and it was intended as a starting point in setting speed limits, not a firm guideline.