https://www.homedepot.com/p/Rust-Oleum-Professional-Striping-Machine-Accessory-2395000/100153299
Home Depot might rent one to you
1. Get a 5 gallon Lowe’s bucket with lid and 3 gallons blue enamel paint. Also get a cheap “Rain Barrel spigot and short length of garden hose to screw onto spigot.
https://www.amazon.com/Rain-Barrel-Spigot-Platic-Seal/dp/B0118CWHGI
2. Drill correct size hole near bottom edge of bucket, on side. 1-1/4” for the spigot above, which might be tricky as surface is curved and thin. Tends to twist your arm when partially breaks through.
Or, use 3/4” wood bit for pilot hol (easier), then widen by breaking off pieces of plastic with strong needle nose pliers. Doesn’t have to be neat or exact. Mount spigot in hole. Use big blob of silicone RTV on inside to seal better.
3. Screw about 5 feet of cut hose onto spigot. Tie strong cord near open end of hose, to pull up to stop flow fast. Wrap duct tape around cord tied to hose, to secure without crimping hose shut, and prevent slipping.
4. Spigot OFF!, fill bucket with paint, snap lid on, punch 1/4” hole in lid for air.
5. Drive slow, guy in back, gate down, hose up!, turn on spigot. Drop hose to start flow, pill up cord to stop. Let end of hose drag for thinner line, lift up for splash effect thicker line.
Practice with 1 gallon first somewhere.
Lots of good ideas in the thread.
I’d probably rig an Airless paint sprayer to a hitch ball mount.
-Prime line, fill with paint, zip tie grip open to ball mount, pointed down
-Attach sprayer ac power line to extension cord in cab of truck
-approach target zone.
-Plug sprayer into a 12v-120v inverter that is attached to a battery.
-unplug at end of target zone.
-Drive away.
A nice .017 tip will probably spit a quart over 300 feet, depending on speed. Priming will use another quart. Have extra.
Obscure plates of vehicle ;)
Might be harder to find the highway painting devices. But maybe a sports field sprayer is easier to find.
Seems like the easiest, least moving parts, simplest ... is a power sprayer and then with a little experimentation you can figure out how fast you can go and still get the line down.
I DO think you want road paint or something made to adhere maybe to concrete. Basement sealer I bet, if you can tint it blue ... would probably be a bitch to get off (in a good way given what you're hypothetically imagining) ... if getting actual road lining paint is too difficult.
Hypothetically of course I might not want to buy the obvious equipment and paint if I wanted to avoid detection. That is, Dateline Mystery is littered with inmates filmed at Home Depot buying plastic bags and axes and duct tape .... and well, just ask the Juicy Smollier team.
So maybe a power sprayer at one place by one person and not-road-but-still-adheres-to-that-kind-of-surface paint bought by another and tint by a 3rd.
Hypothetically right? You're talking about writing a crime novel? Thought so.
If neatness doesn’t count, put a 50 gallon drum, on its side in the bed of a pickup truck, position it at the begin point, have someone pop the cap; then pop the clutch.