Not much help to give really. Somehow you have to explain why you missed those signs, and following satnav is not sufficient reason, sorry to have to say it. The signs are reflective so would have shown up in your headlights. We are seeing so many cases now where the driver was obeying satnav instructions, and not seeing signs that bar progress. Would you have gone past a traditional No Entry sign ? No, because most have been there for a few years so satnavs have them recorded so wouldn't have directed you past one, but there has been a huge roll-out of bus gates buslanes, and Low Traffic Areas, and the signs for these seem to escape people's attention.