Honestly, this is kind of an unanswerable question, as no one knows anything about how it was determined that your "standard" road size is 54cm, your cycling frame of reference/experience, what your measurements are, or how you ride. Some are of the opinion that, in general, riders often ride a frame that is actually too small for them to save marginal amounts of weight over a larger frame and compensate by having long seatposts and stems. Can you ride a 57? As the last poster said, "sure, why not?". You may not be happy with the fit, but if a 54 truly is a frame that generally fits you, and you need no accommodations to long/short torso or legs, a 57 is not likely to fit you well. Depending on where you started, a 57 could be the ideal size for you based on various philosophies about fit.