高速

1. Origins, structure, and basic meaning

• Structure: 高速, read こうそく, denotes high speed and can adverbially describe transmission or movement.
• Basic usage: 高速でデータを送る modifies data transfer; 高速で走り抜ける modifies a train's motion.

2. Common pitfalls and similar expressions

• Manner phrase 高速で
  • In both clauses で turns high speed into the manner of an action; neither context names an expressway or facility.