I'm not sure the systems available in N. America, but Moscow (the Russian Capital) has heated streets (steam pipes running underneath the roads). It certainly works. I guess it depends on the system you are looking at.

Techo-Bloc (the paver manufacturer) did a heated driveway as part of their feature project in New England a couple of years ago. I'm not 100% sure but I think it was Interstate Landscape Co in Londonderry NH who did the actual installation. You can find their website here. They can probably give you more info.

We design, sell, and install heated driveway systems across North America.

A proper snow melting system will be designed to ASHRAE standards for your geographic region. ASHRAE reports localized data on snow melting and the heat needed to maintain a proper melt. We have many systems in the Boston area and they all perform very well.

For more on this: http://www.warmquest.com/radiant-heat-applications/snow-melting

As with other things, it's not just the initial cost but the operating cost. I have seen a heated system in action (Potter County, PA - a very heavy snow area) and it worked flawlessly.

i'd be interested to know, also. seems you need to have perfect water collection at the bottom of the driveway or you'll end with an ice rink in the street.

I wonder if OP went ahead with the heated driveway? It’s been over two years since we have heard anything.

Regarding operating costs. One of the great things about electric snow melting is you know ahead of time exactly how much power it will draw when turned on. This lets you plan and budget for operating costs very easily.

The electrical systems never idle and are either on or off, so they are only impacting your electrical bill during a storm while melting snow.

how does it handle the water runoff?

It's permeable too! Cool deal, just make sure it's installed properly. It's the installation that makes the permeable work, not just the tile/brick.