The U.S. is having a streak of cold weather, even Florida was 32℉ yesterday morning. That's freezing folks- in FLORIDA! And so, when I saw this sign, I realized that it could possibly happen in Florida, but very unlikely.
Now the sign gives a "speed limit" and that doesn't change, no matter what the climate is like. The old testament law was like that- it didn't change, period! Then Christ came and fulfilled the law (perhaps completed might be a better word).
And even if we should sin, we have hope because of what Christ did. Paul said...
Ephesians, Chapter 2 (World English Bible)
11 Therefore remember that once you, the Gentiles in the flesh, who are called “uncircumcision” by that which is called “circumcision” (in the flesh, made by hands), 12 that you were at that time separate from Christ, alienated from the commonwealth of Israel, and strangers from the covenants of the promise, having no hope and without God in the world. 13 But now in Christ Jesus you who once were far off are made near in the blood of Christ. 14 For he is our peace, who made both one, and broke down the middle wall of separation, 15 having abolished in his flesh the hostility, the law of commandments contained in ordinances, that he might create in himself one new man of the two, making peace, 16 and might reconcile them both in one body to God through the cross, having killed the hostility through it. (emp. added vss. 13-16 GDR) 17 He came and preached peace to you who were far off and to those who were near. 18 For through him we both have our access in one Spirit to the Father. 19 So then you are no longer strangers and foreigners, but you are fellow citizens with the saints and of the household of God, 20 being built on the foundation of the apostles and prophets, Christ Jesus himself being the chief cornerstone; 21 in whom the whole building, fitted together, grows into a holy temple in the Lord; 22 in whom you also are built together for a habitation of God in the Spirit.
Now, the physical sign is like the old law, unbending, clear and inflexible; but the Law of Christ lets us see through what God wants us to do and understand the reasons behind the rules. In other words, the difference between the life of a child and the life of an adult.