To clarify, for circumstances to constitute a defence, as opposed to mitigation, the accused would have to believed that there was a real likelihood of death or serious injury to himself or another and that breaking the law was a reasonable way to reduce that likelihood.
Other jurisdictions have a defence of necessity - where choosing a lesser evil can be justified, but here, it is only effectively where you have no choice - the risk of death or serious injury being beyond that which someone could be deemed to choose.
Whether an action was reasonable, when facing some peril, should be assessed from the perspective of a reasonable person facing such peril with decisions made in the heat of the moment, but your choice to continue driving on the basis that you didn't want to get a fine for stopping on a red route (taking a mildly cyncial view) is not a position I would like to have to try to defend.
