• 速はやめる — to speed up; to make faster verb (trans.)
• 速はやまる — to become faster verb (intrans.)
• 高速こうそく — high speed
• 速度そくど — speed
• 速達そくたつ — express delivery
• 速すみやか — prompt, swift
• 加速かそく — acceleration
• 速歩そくほ — fast walking

The radical 辶 (しんにょう) represents movement or a path. Combined with 束 (bundle), the character 速 implies something bundled and moved quickly — a metaphor for speed and swift delivery.