I would say ... backfill it in with pea sized gravel to within 2 inches of average surface, and then asphalt over the top with driveway patch materials.

What caused the ruts? What is the rest of the driveway made of? Are the ruts in a low area that is subject to holding water? Why is there asphalt 12 inches below the surface, is it part of the driveway pavement that has sunk down?
Filling the ruts with gravel might be a temporary fix to keep from damaging your vehicles for now, but a more permanent fix depends on what the underlying problem is.

Don't know what caused ruts- also happened on 1 of city streets & always had to get in other lane for years, before last election they fixed it so only took about 20 years. Since I asked on here I talked to owner of building & sounds like utilities company wants to go under the driveway & they will repave the whole thing for us. Sounds great to me!! Thanks for answering me! Appreciate it! My guess with both streets would be something wrong with asphalt- seems like it is more tar & not enough of solid stuff. The street would get really soft during hot weather, if somebody went through it , it would be spread up the street a bit. I'm just guessing. Both cases the bottom of hole had a good layer of tarry stuff, occasional you would see tire tracks in it then after few days when you went by again they would be gone like they melted back down. Big trucks went by that street daily, most moved over. It's an industrial area. Very weird.

Mmm ... sounds like someone used substandard substrate material (loose packed, so it gave way under pressure from heavy loads driven over it), and some low grade asphalt on top for poor measure.

Well, if they're going to fix the whole thing for you, it might be worth waiting for it to get done, but if they're just going to fix the section that they're going under ... that wont help you much at all.

The whole idea behind the paved road approach is ... you need a substrate that will support the weight that will be trafficking on it on a regular basis without shifting under the load. This substrate needs to be stable, without simply washing away or getting soft due to weather conditions ... pea gravel that has been packed or simply cant move because it's in the bottom of the rut qualifies fairly well for this.

On top, you have the asphalt ... it's not there because it's hard, but more because it's soft and sticky and refuses to move for weather. Over time, it loses it's surface stickiness, but is still a gooey mass underneath, held down by it's own weight. Your patch will need to be glued in pretty good with the asphalt on either side of the rut, so make sure that it's fairly clean and mound it up a bit in center ... pack in in there really good with one of those heavy dirt-packing tools or something similar ...

It might work to lay down a large number of boards and slowly drive over the area with your truck to mash it down, sort of a poor-man's steamroller ... load the truck bed down with dirt or something.

I agree with Skie.
Sounds like substandard work from the get go.

If you do not have a good solid base to lay black top on. It will rut out from simply being driven over with even a passenger car,

Dumping Pea Gravel into rutted black top will not solve the problem just compound it over time once water gets between the gravel and what ever is laid on top of it.

Good deal on Utilities company willing to repair the damage for free.

There is large area for at least 50 cars on 2 levels & 2 driveways all the rest is fine. May have been at tail end of paving job & not properly mixed. When I got cement put along side of my house after quake I noticed as cement truck was pouring the last little bit wasn't properly mixed, I complained but there were so many pour & run guys trying to make a buck, my contractor didn't like it but said it should be OK. I had laid rebar & chicken wire all along there they said "oh, that's a good idea. Well the bad area is bad & the 1st 2 inches have come out about 12in.long & 4in wide & all that is left is aggregate so if it ever rains it turns green , needs to be repaired, have a list as took care of folks for 4 yrs until they passed, sure did get behind at my home but glad I did it. Thanks for all the advice, I'm printing it out. Utilities company said they would do whole driveway, it's not long maybe 50 ft. 1 car wide plus few ft.