I have been trying to shut the water from the street off in order to replace a failed meter coupling. The ball valve on the street side is almost completely frozen (about 30 years old). It is full of water, so heat isn't worth thinking about. Any suggestions other than having the city turn off the street valve?

Loosen the nut just a tad and try turning. The packing may have gone hard or caused a bit of corrosion that's causing things to bind. Those things are solid brass so its unlikely its "rusted" open.

FWIW, isn't the meter the city's responsibility? I'd call them first. Worst they can say is "no".

Here, it depends on where the valve is located, the meter and everything upstream belongs to the city, downstream of the meter it's mine to deal with. With the comment about the street side of the meter I suspect the valve is the city's issue to deal with if thw OP wants to deal with the city. Might even be illegal for him to touch it.

I was thinking that too.

If it’s before the meter, it’s the city’s problem. If after it’s yours. I turn off the city valve all the time on my rental units to repair lines inside the house.

Not in every municipality...

In ours everything downstream from the main (excluding the meter itself and meter shutoff valves) is mine to deal with. DAMHIK.

Yup. In my town the city is responsible up to the curbstop. After that everything, including the meter, is the homeowner's responsibility.

Well its worth a damn phone call to find out !!

The last time I had them shut it off at the street, they broke the curbstop. That cost me $1500 in 1990 dollars.

Video it, then make them eat the cost if they do it again.