Being in the People's Republic, you listen up to what the people want. Add to that Swiss quality (detail wise; Swiss quality on the soccer fields means we are just short of 500 minutes of regular World Cup play time without being scored upon), and you get today's insider on Line 3. (Here it is, xidandave!) If there's a bit of Swinglish (Swiss English) in the thing, forgive your Beijingologist. He's still in Swiss Mode after the team won last night's game. :-)
It's a dead giveaway. You don't need Swiss precision to sniff it out. Subway plans for 2015 will foresee Lines 1, 2, 4, 5, 6, 7, 8, 9, 10, 13, 14 and 15, but no Line 3. There are Line 3s in Shanghai and, as of next year, in Tianjin. But no Line 3 in our capital — it seems — until you realize it's in the works!
Line 3 will be yet another west-east line. (Yep. It sure is boring. Until you experience Line 1.) It is likely to start off at Tiancun or thereabouts in western Beijing, and looks set to connect to the Mentougou Maglev out west. (This is between the western 4th and 5th Ring Roads, for those of you with a map lying about.)
Line 3, heading east, makes a first call with another line at Xidiaoyutai station (地铁西钓鱼台站), where it's meeting up with Line 10. It heads under Fucheng Road and Fuchengmen Inner and Outer Avenues, also meeting up with Line 9 at Baiduizi (地铁白堆子站), Line 2 at Fuchengmen (地铁阜成门站) and Line 4 at Xisi (地铁西四站). In longer-term plans, it's also likely to meet up with the planned Line 12 just east of the Lines 3 / 9 interchange. Line 3 next continues as a solitary metro warrior next to Fuyou Street (think a zillion government complexes) and Shatan, around the southern gate to Beihai Park. (How it's going to get through the Northern and Central Lakes is going to get complex.)
Line 3 is married, even if just for a bit, to Lines 5, 6 and 8 at the colossal interchange by the Art Museum and Dongsi, where it has a direct link to especially Lines 6 and 8. It then flips sharply north, having its own "private date" interchange with just Line 5, the Romantic Mozart Line, at Zhangzizhonglu (地铁张自忠路站). It next heads further east, finally making use of the reserved platforms at Dongsi Shitiao (地铁东四十条站). If you're not a Shunyi-ite, get ready for this: it then makes a stop in the Sanlitun area at the Workers Stadium before finally connecting to Line 10 at Tuanjiehu (地铁团结湖站). Its final interchange with a "near-term" line is at Chaoyang Park (地铁朝阳公园站), where it mixes at matches with Line 14. There will be interchanges after that, but it's mostly with planned lines and a few mysterious light rail lines as well. It continues east past Pingfang (平房) on the eastern 5th Ring and finally enters Dongba (东坝), yet another mega city on the outskirts in the making.
Note: Everything you've heard about Line 3 is in the works (it's likely to be reality around the 2015-2020 timeframe) and is for reference only. Do not raid your Beijingologist's (supposedly-)Swiss bank accounts to either borrow cash to buy real estate in Dongba or if you bought your house early — only to find Line 3 won't stop by your place!