* Van Vleuten went head first into roadside banking * Organisers say she was conscious when taken to hospital (Adds details) By Martyn Herman RIO DE JANEIRO, Aug 7 (Reuters) - Dutch cyclist Anna van der Breggen produced a perfectly-timed burst to snatch Olympic gold in a dramatic climax to the women's road race alongside the Copacabana on Sunday. American Mara Abbott was left as the sole leader on the flat run in to the finish line but with victory tantalisingly close she was caught by Van Der Breggen, Emma Johansson of Sweden and Italy's Elisa Longo Borghini. Johansson took the silver, Longo Borghini the bronze and it was heartbreak for Abbott. More...