What's the name of the Tokugawa policy that only the Emperor can drive on wheels in the roads of Japan?

I was wondering what the reasons for the ban were, besides slowing down troop movement and avoiding damage to roads. But throwing these keywords at google didn't produce results: 輪　禁止 天皇　将軍 徳川　幕府 勅令　歴史 鎖国

A link to the original text of the edict/policy would also be greatly hugely appreciated!

Please help!

I don't think there is any particular name for it.

Japan back then was a united nations. The law varied depending on where you were. And the Tokugawa period spans across 265 years. Surely, the law in the states today is different from the one 265 years ago. There had been a law similar to that in Kyoto but that dates back to 平安時代 (長保元年令 in 999 dictated only nobles higher than 6th degree 従六位 could be on a cow drawn carriage 牛車 in Kyoto) so it was not particularly a Tokugawa policy. And Japan is so mountainous wheels weren't that effective back then anyway.

The more important, and well known ban is the ban of building large ships in the early Tokugawa era. The law is called 大船建造の禁.

Thank you for the help Masaman.

Is the original Japanese (period or modernized) text of such policies regarding wheeled traffic available online anywhere? A version of J-STOR or Wikisource which hosts Japanese documents? (Japanese language version of Wikisource doesn't host many historical documents at the moment:

http://ja.wikisource.org/wiki/Wikisource...4%E5%8F%B2 )