Well, maybe not yet, but a proposal to build an underground expressway network including four north-south routes and two east-west routes that span the city seems to gaining momentum. A recent paper presented at the Hong Kong Society of Transportation Studies conference presented algorithms for identifying entrance and exit locations. Coauthors included engineers from the China Academy of Transport Sciences and Beijing Jiaotong (Transportation) University.
These underground roads would be in addition to the six ring roads that circumnavigate the city of nearly 20 million people. Adrian Moore and I discuss these transportation planning concepts (including a discussion of Beijing, Shanghai and other Chinese cities) as central to 21st century approaches to addressing congestion and improving mobility in our book Mobility First: A New Vision for Transportation in a Globally Competitive 21st Century (Rowman & Littlefield, 2008).
Of course, the challenge will be building this network. Fortunately, unlike the U.S., the Chinese approach transportation projects from a "benefit" perspective, rather than a cost-constrained perspective. Their view is: "If its worthwhile and has public benefits, how do we get it done?"
Notably, the Beijing underground expressway proposal was floated in a 2006 International Academic Conference on Underground Space.
In the past, China has built infrastructure using public private partnerships, relying on private capital to infuse cash and manage the project to keep it on budget and on time.
Increasingly, however, China will also have to focus on optimizing the network as well as funding it. That will mean more tolling using the latest road pricing technology to maximize travel speeds and times. Beijing already has one of the world's most advanced systems for monitoring traffic speeds and levels, using GPS devices mounted on 10,000 taxis to give citizens and officials real time reports on traffic (and accessible via the Internet).
Meanwhile, in the U.S., the idea of building underground is considered heresy everywhere except for transit lines. Perhaps its time to join the Chinese in the 21st century.