Among Roman contributions don't forget the arch, modern concrete, the modern highway of which many are still in use in Europe and the British Isles.
You forgot sanitation. The romans had good sewage systems and organized garbage pickup. Also, they had good public water systems.
Not to mention law, the preservation of the glories of Greek Civilization, and the spread of Christianity throughout the West. Too bad they succumbed to Decadence. Too bad it's such a strong influence in the West today.
As you see, the Romans didn't spend much time in Gaul.