I have noticed that the word broad is quite often pronounced in the wrong way by nonnative speakers. Therefore, let me discuss the different correct and incorrect variants. Let us consider the correct pronunciation first. In BrE, we have [brɔːd], while in AmE it is [braːd] (listen here). Even though the OED gives the same phonetic spelling for BrE and AmE, see here, the sounds are quite different. This difference is captured by [braːd], as listed in the Longman Pronunciation Dictionary.
Interestingly, quite a number of people pronounce broad incorrectly, namely such that it rhymes with road. This mistake seems quite understandable, because road and broad have similar spelling. Nevertheless, the pronunciation of the oa is quite different in broad and road. This difference is obvious from the phonetic spelling, which is [rəʊd] for BrE, and [roʊd] for AmE. Listen to both versions here and compare the pronunciation to that of broad here.