This game is not called Road-kill Enthusiast. Neither is it called Pedestrian Pancake-Maker. Ubisoft could have called it The Walking Died, but they didn't; firstly, because that's a stupid name, and secondly, because pedestrians don't die in this game. Or at least, you can't run them over; I like to think that after a day of perfectly timed evasive jumps away from speeding cars, there's a line in the code which has them suffer a fatal stress-induced heart attack just before bed. Or perhaps their endless paranoid rambling about drivers 'hunting them down' results in a wrongly diagnosed persecution complex, and they end up hanging themselves after taking a Risperidone overdose (but not before their partner leaves them and they spend several years miserable and alone, sobbing into the tawdry fur of their arthritic pet cat, Steve, who's enormous vet bills ultimately bankrupt them, forcing them to live in a house of cardboard and rusty cat-food tins, occasionally selling off semi-vital organs for smack).
You see, every NPC you encounter has a unique personality and back-story; you might Shift into a car and hear an overbearing wife berate her husband for his constant forgetfulness, or sit next to a bitter driving instructor as he bullies a wide-eyed pupil. You might help a couple of teenagers transcend their shady family business by (ironically) earning college tuition money in illegal street races, or elicit a high-speed police chase for a pair of jovial cameramen working on a D-grade TV movie. Instead of a jaywalking murder sim, you get a huge cast of 200 fully voiced NPCs with over 30,000 lines of recorded dialogue (out of a total of 50,000-odd lines in the entire game); anyway, you're a cop, so victimising innocent civilians would be totally out of character.
Except... you're not always a cop. Well you are, it's just that you're often... err... inside other people. At any time, a single button-press lets you escape your Earthly form and zoom out high above the city, slowing the in-game action to a crawl; here you're free to select a new vehicle, Shifting your consciousness into the open vessel of another driver's body. One moment you're riffing with your wise-cracking partner on the way back to the station, the next you're inside a middle-aged paramedic, racing to get a dying patient to the hospital. It's an efficient mechanic, and one that intelligently streamlines all that messy car-jacking and head-stomping that other free-roaming games rely on for switching vehicles.
And that patient in the ambulance is you. Turns out you're in a coma after a particularly bad car crash. Some nutter called Jericho escaped from a police van on his way to trial (assisted by a rocket-launcher-wielding news-helicopter femme fatale), 
and in the ensuing chase you smacked your head very hard indeed. Hence coma, and hence weird Shift-power thing - it's all in your head, probably.
Creative license duly earned, the early part of the game has you tracking down Jericho while your subconscious communicates with you via in-game billboards. As you can imagine, that Shift power comes in rather handy for a policeman in the seventies; why bother chasing a speeding criminal, when you can just Shift into an oncoming Lorry and smash them off the road? Clearly no inconsistency there. Apparently you wake up for the second half of the story, but the developers were talking about Inception rather a lot, so don't be too surprised if it turns out the whole thing was a dream (no-one mentioned Dallas for some reason).
Between each Story Mission you need to complete a few City Missions to earn the right to re-enter your body and progress the game. These generally involve altruistic attempts to aid the citizens of San Francisco; initially the challenges are pleasingly inane (such as extorting cheaper lessons from that harsh driving instructor by driving aggressively into oncoming traffic) but later they're said to tie in more closely to the main story, with characters commenting directly on the on-going manhunt. City Missions fall into a number of categories, from Stunt missions and Races to Takedown side-quests (which have you chasing another car in an attempt to ram it off the road) and each has its own characters and dialogue to provide context. Naturally, the Shift mechanic can be exploited in almost every situation, allowing you to set up a series of cars for that perfect stunt shot, or ram rival racers off their line by misdirecting nearby traffic. There are certain limitations imposed for the sake of gameplay however - you can't Shift into other mission critical racers or Takedown targets and simply drive them off into disaster - that would be too easy.
Occasionally you'll come across a Dare while exploring San Francisco (such as driving at 60mph for 20 seconds without crashing); these challenges flash up as green dots on your map and earn you Willpower Points which you can spend in the many garages dotted about the city. 140 licensed vehicles are available for purchase and upgrade, and everything you buy (including the garages themselves) generates further income in turn, so you're never likely to be too short on cash.
Special mention is owed to the efficient interface and control system Ubisoft Reflections has implemented for the title; your mini-map expands with a single tap, and on-screen objectives or hints are never more than a button press away. Mission-relevant vehicles (such as police cars, or tow trucks that double up as handy ramps) appear on the map contextually, and your next expected location is always clearly marked and visible. This is not a game that will have you endlessly setting way-points, or checking menu screens to figure out what you're supposed to be doing; indeed, it's shaping up to be a fairly simple, focused affair, made interesting by its innovative Shift mechanic and range of fully-voiced NPCs. 
Although it's yet unclear whether the loosely strung together missions we experienced will ultimately result in a coherent, compelling single-player narrative, Reflections' efforts to streamline the gameplay of Driver San Francisco suggest that it's at least heading in the right direction. That's a sign we're always pleased to see on the route to release, and it doesn't seem as though it will change lanes or pull a design u-turn any time soon.