China

National Highway
The "G" prefix stands for guojia, which means "national."
Shanghai expressway

Hong Kong

All Hong Kong images are licensed under Creative Commons Attribution-Share Alike 2.5.

Hong Kong numbered route

Source: Wikimedia Commons

India

National highway

Israel

Motorway
Primary road
District road
Local road

Japan

Primary highway

Malaysia

Selangor Route 11. The single letter prefix stands for a Malaysian state or district:

J: Johor, K: Kedah, D: Kelantan, L: Labuan, M: Melaka, N: Negeri Sembilan, C: Pahang, A: Perak, R: Perlis, P: Pulau Pinang, S: Sabah, Q: Sarawak, B: Selangor, T: Terengganu, W: Wilayah Persektuan Kuala Lumpur

No prefix designates a federal highway.
The prefix E designates a toll highway.


Taiwan

National Freeway System, analagous to the Interstate Highway System in the United States. The shape of the sign represents the plum blossom, the national flower.
Provincial Route
County Route

Thailand

National Route. The figure above the number is a silhouette of the national symbol of Thailand, the Garuda, a mythical half-bird, half-human figure.