The road to hell is paved with good intentions – just ask General Motors.

Pressed in the early 1990s by a looming California mandate that was going to force auto makers to sell thousands of zero-emissions vehicles in the state as early as 1998, GM spent more money and worked harder than any other auto maker to create an all-electric vehicle that consumers actually would want to buy.

Aware the car would be hampered by a limited and unpredictable cruising range, engineers created a vehicle they thought would sell: a 2-seater that was fun to drive.

Toyota chose a far less ambitious route to meeting the mandate, an electrically powered version of its small but practical RAV4 SUV.

Both vehicles – one sporty, one practical – failed miserably for reasons that now are obvious: Consumers will not spend their hard-earned dollars on vehicles that only can go 90 miles (144 km) and take six hours or more to recharge.

Did GM ever get recognition for being a leader in the EV movement? No. Instead it got skewered in last summer’s absurd (but popular) documentary film “Who Killed the Electric Car.” The movie argues GM deliberately sabotaged its $1 billion EV-1 program.

The movie is so unfair that even Toyota stuck up for GM. Toyota Motor Sales Vice President Ernest Bastien told the Detroit Free Press recently that film maker Chris Paine deliberately ignored Toyota’s similarly horrible marketing experience in order to build a better case against GM.

Sadly, GM’s extensive efforts to bring emission-less hydrogen fuel cell-powered vehicles to market are not faring much better in the court of public opinion. Many environmentalists call GM’s hydrogen efforts – on which it so far has invested more than $1 billion – yet another scam.

Now GM is sticking its neck out again, becoming the first auto maker in the world to commit to building a plug-in hybrid-electric vehicle, the Holy Grail vehicle that environmentalist groups have been demanding.

And yet, the response from the environmental community – while positive – has been far from overwhelming.

Plus, a surprising number of critics from inside the industry are piling on, including our own Jerry Flint. They’re all clucking the lithium-ion batteries needed to make PHEVs possible are a pipedream, and that GM shouldn’t bother.

Three years ago, diesel engines clean enough to meet Tier 2, Bin 5 emissions regulations were pie-in-the-sky, too, Jerry. Now a string of new light-duty diesels capable of meeting California’s most stringent emissions standards soon will be widely available.

GM has made plenty of mistakes over the years: from shifting too many resources to light trucks at the expense of passenger cars, to being embarrassingly late to the HEV party, but it deserves more credit than it’s getting from environmentalists and the industry at large for its bold move into PHEVs.