Read it on Today on Bing, here's the whole paragraph:
The Pont Fawr is itself the stuff of history: Built in the 1630s, it's often called the 'Inigo Jones bridge' after the pioneering early modern architect who, legend has it, designed the triple-arch span that today carries motor traffic. A one-way bottleneck along an otherwise two-way main road, the bridge's humped shape tends to obscure oncoming cars, earning it yet another local nickname: Pont y Rhegi (Bridge of Swearing).
I don't get this part, " A one-way bottleneck along an otherwise two-way main road", what does the 'otherwise' mean? Does it mean the bridge has 2 roads, one is a one-way bottle neck, the other is a two-way main road?
Need your help! Thanks!!! I'm not a native English speaker.