Would anything less than yes or no and a Bible verse specifically addressing the issue be a satisfactory answer? Seriously, what kind of thing would constitute a satisfactory answer? Like.. what form might a satisfactory answer (to this question) take?
This is truly an ethical and philosophical question, if one chooses to address it as such. Because it is posed to a 'Christian' it must necessarily involve the true spirit, or higher intent of the law. The OT addressed the literal, written law, or in this case, the actual speed limit on the road travelled.
Because the OT laws were considered our 'schoolmaster' (as described by Paul) younger Christians, still needing strong literal boundaries, probably should view the speeding laws as such: a firm literal yardstick to measure behaviour. That young people are usually unable, or unwilling, to drive properly/lawfully, the legalistic aspect of the traffic laws should, and often does, apply. They usually cannot see beyond their desire to 'go faster' and the 'unreasonableness' of such laws in the first place.
The mature Christian sees the wisdom, and the necessity for such laws, far beyond their obvious safety value. That speeding is dangerous, expensive, and damaging to the social order is also clear. It's one of the 'thousand cuts' that are slowly killing us. Knowing this, as many older people do, is enough to goad the conscience into obedience to these laws, not grudgingly, but understanding their true value. Failing to do good when one knows to do so,
is a sin to him/her.
So, to the immature person, speeding is no sin, as they see no 'good' in obeying the speed limit. They speed with impunity, and a clear conscience.
To the mature, who see the damage done to a nation that collectively bends and breaks a variety of laws,
it is a sin.
owg