It's a pretty basic premise: Get out of the city using your car as a battering ram. You race through several obstacles, hitting zombies. The military is hell-bent on keeping everyone in the city too, so you'll have to deal with them as well. To keep things interesting, there is an upgrade system to get your car in order. It's not the deepest thing in the world, but it does add a layer of strategy to the whole affair. For instance, you'll need to add reinforced glass and wear a Kevlar vest to deal with a helicopter when it comes down, but you'll also need to upgrade your tires to deal with road spikes.
For all its charm, there are a few problems with Road of the Dead, namely the repetition of it. The scenery doesn't really change or offer any variation, and the gameplay can get a bit stale. There's also the problem that it can't be shifted into a full-screen view, which for a first-person driving game is a bit difficult to wrap your head around at first. That said, this is a Flash game, not a $60 investment, so the fact it's entertaining for at least 15 minutes should be enough to cover any breaks at work you have today.
If you've got a hankering to play an Outrun-style game with hints of Carmageddon and zombies, then you'll be in heaven. Even if you hate zombies, there is still something to enjoy here while you pretend to work. It's certainly not the greatest achievement of the medium, but it does stand apart as one of the better zombie games, and it certainly fits in nicely with a Halloween motif.
Play it here.