Generally it's an undesirable characteristic, but because of that you may get it cheaper than an equivalent house on a quieter stretch.
There is a safety element to it like all roads, however I'd be more concerned with other quality of life issues, most notably noise, but also parking as mentioned by Sue Ellen. Have you been inside the house and listened carefully for the noise? Does it need new windows? Who will be sleeping in the rooms facing the road? From the garden, can you hear it clearly? Would that annoy you?
It's a tricky one to decide on, because what might not bother you at 2 pm on a Saturday viewing might bother you a lot more at midnight on a Tuesday. Also, it may not bother you, but might drive your spouse nuts.