Friday I saw the darndest thing. Location: Northern California Highway 101 North of Santa Rosa. Action: Caltrans truck spraying oil on the shoulder. Comments: It looked like a converted water spraying construction truck that is used to keep dust down during grading, but it was spraying oil. I know it was spraying oil as another truck was driving slow a hundred yards behind it, effectively closing the slow lane (right most lane), with a big sign saying somthing close to, “Oil Spraying Ahead”. I also noticed that there were pieces of plywood over the drains with sandbags on them.
Why would they do that?
Could it be in preperation for adding an additional lane, or weed control??? <—speculating wildly
I would think it’s for weed suppression or vector (insect or mosquito) control. Here in Alabama, the Highway Department mixes pesticides or herbicides into diesel fuel or kerosene to spray on the right-of-way. The sandbags and plywood are to limit the amount of pollution reaching nearby streams.
Note: California environmental regulations are much more stringent than Alabama. You might want to contact Caltrans - (916) 654-5266.
It used to be common practice to spray oil on dirt roads in rural areas to keep the dust down. The oil would bond with the dirt/gravel and become lightly polymerized by sunlight, and act as a cheap sealant.
I grew up in South Carolina where this was common thru the early 70’s. Until they realized that the PCB-laden transformer oil was a really really bad thing to be spraying willy nilly about the place.
If CalTrans was spraying oil on the shoulder, it was probably dust control… possibly in preparation for imminent roadwork. The covered storm drains are a good clue. Water only works until it evaporates. Oil doesn’t evaporate completely. And oil is not a very effective way to control weeds. Water is a much better way to distribute herbicides.
Another thought: They wouldn’t be chip sealing the shoulder, would they?
Chip seal is when they lay down a light coat of oil, a lift of pea gravel (or smaller) on top of that, and let the oil “glue” the wearing surface (the gravel) to the course underneath. Then either they compact it or let the traffic driving over it compact it, then sweep up the excess gravel.
I wouldn’t use it for an actual traffic course on bare compacted dirt at all. Not strong enough for continuous use, but maybe a shoulder?
I dunno, thoughts? I’m just throwing out a possibility. SandWriter, were they spraying the “oil” on bare dirt, or an asphalt shoulder?
[QUOTE=bughunter]
It used to be common practice to spray oil on dirt roads in rural areas to keep the dust down. The oil would bond with the dirt/gravel and become lightly polymerized by sunlight, and act as a cheap sealant.
I grew up in South Carolina where this was common thru the early 70’s. Until they realized that the PCB-laden transformer oil was a really really bad thing to be spraying willy nilly about the place.
[QUOTE]
I don’t know how to break this to you, but… I live in Orange County, New York. They oiled my road a MONTH ago. They use the identical method described- they follow the oil truck with gravel spray. After a week or two, the dust and filth settles down and it is the poorboy approximation of resurfacing.
Hrm, if they had sprayed it onto a “bare dirt” surface, I would have agreed with the majority that it’s just a dust cover. But, can you let us know if they follow it up with a lift of pea gravel?
But, I’ll put the next DopeFest pitcher of choice they’ll be chip sealing the shoulder. Any takers?
Tripler
Now if they’d have drizzled it into the cracks, then I’d agree with DrDeth.
There are no sidewalks on my street- nor any shoulder at all. People walk in the roadway, drivers watch out. How is the pea gravel dangerous?
Trashes your undercarriage.
Is sprayed backwards violently when cars accelerate from the stop light. Thousands of small projectiles.
Causes skidding/ collisions because it takes at least a week for the tires to slowly impress the pea gravel INTO the layer of sprayed oil, making for a new “surface”.
The fine stone dust that is part and parcel of dumped pea gravel makes for miserable breathing. ( I’m athsmatic ).
So yeah, for the first week at least, it’s environmentally and physically unsafe.
