One quick tip: on Google Maps, do a search for 24hr places that serve coffee, food, or gas along your route... Dunkin Donuts, Starbucks, truck stops, etc... Choose one and scroll down through the business description until you see "popular times" while they don't give you any numbers to work with, the graph gives you a pretty good indication of how busy the store is at different times of day and from this you can infer how busy traffic will be. Note that you can change the day of week that you're viewing. You can get a feel for it by checking places you're personally familiar with. It's not perfect, but it will give you an idea
For instance the first screen shot is my local Dunkin Donuts that has a 24hr drive-thru... You can clearly see when church let's out on Sunday, the second screen shot is a Denny's, a 24hr restaurant, on the 101 in McKinnleyville, in northern California. looking around town at different venues like the grocery store, some restaurants, gas stations, etc, almost nothing is open 24 hrs except the grocery store and the Dennys, not even the gas station is open from this I would infer that the amount of traffic coming through town isn't typically enough to stay open through the night for. However, compared to my home Dunkin Donuts you can see that during the day it gets pretty busy, and pretty early.
Sent from my SM-T817V using Tapatalk