At work we have a tarmaced car park that had a hole cut out to gain access to underground services.
I'm able to get some tarmac and a wacker plate but when it's done properly on highways etc it's kind of sealed to the existing tarmac using hot bitumen. I dont have any and it's not practical for me to purchase some and heat some up.
You need the right equipment - heating oven and blow torches etc.and the bitumen comes in large cylinders, probably too much for a small patch type job. However, you can also get liquid primer to do a similar job. I suggest you try a good builders' merchant.