Agree with above. But let me add that it's pathetic (or unfortunate, depending on your point of view) that with 26 characters in the Roman alphabet, China decides they'll again use "G" to stand for their national expressway system (for Guojia gaosu, or 国家高速), with one or two numeric characters afterwards.

While the old national highway system still maintains the same "G" prefix (for Guodao, or 国道), with 3 or 4 numbers following.

So confusing, like lots of things in China.