A great idea that's not ready for prime time: That's OnStar Turn-By-Turn, which at the press of a button connects you to a friendly operator who looks up and downloads navigation directions to your car--assuming, of course, that the operator can find where you want to go and that atmospheric conditions permit a download.

I drove using OnStar Turn-By-Turn (free the first year, then probably about $10 a month beyond the cost of basic OnStar) a couple months back in Detroit, in a car full of GM engineers and PR people. To use it, you just press the OnStar button on the mirror and tell the operator where you want to go. He or she looks up your destination, then downloads route instructions to a rudimentary GPS system with a one-line text display and a directional arrow on some models, and you're off. It worked well then; not so well when I was turned loose on my own, though.

Weekend from Hell

I set out in a Cadillac DTS with OnStar Turn-By-Turn, and began my weekend from hell. For a couple locations in the Adirondack area of New York State (that are both in Yahoo Maps and Microsoft Streets & Trips), the OnStar operators couldn't find a long-established road or even the road leading to that road. They could find the nearest town seven miles away (but had trouble downloading the directions for me) and a bigger town 65 miles away. OnStar also couldn't locate a been-there-forever country road in Keene, NY, and that's with OnStar having access to both of the major computerized roads databases from NavTeq and TeleAtlas (formerly GDT).

My first eight calls to OnStar yielded two on-holds of 10-plus minutes before I was cut off, and the service made six failed attempts to download the information. OnStar blamed poor cell coverage and/or system problems. When I made my first few calls, I was working my way through traffic on Interstate 287 in New Jersey, near Interstate 80, and heading toward the New York State Thruway. If there was lousy cell coverage in one of the most populous areas of North America, my Verizon phone didn't know about it. It showed three bars, four bars, and just occasionally, two bars of signal strength, and OnStar uses the Verizon network.

The operators were invariably polite, but sometimes I got the feeling that they were chosen for their affordability over their efficient and speedy problem-solving abilities. When I later talked through the problems I had with Nebo Nedeljkovic, OnStar's online service manager, he was able to locate two of three roads. He told me, "Although infrequent, there are incidents as you experienced."

To be fair, if OnStar operators find the location you need but the OnStar technology can't download the GPS routing, there is a fallback: The operator can speak the instructions, the car records the voice (up to 90 seconds), and you can play back the instructions as needed.

Other Limitations

Assuming you can get route instructions downloaded (I had better luck on other days), going from city to country is no problem. You don't need cellular coverage at the end of your journey, only the GPS satellite network. But if you're in the scenic middle of nowhere tomorrow and can't get cell coverage, you can't call for routing for the second day's trip. And unfortunately, you can't ask OnStar to download and cache today's trip and tomorrow's trip. Only one trip can be in memory at a time.

OnStar downloads a route corridor of information to get you back on track in case you make a wrong turn or pull off the interstate for fuel, but it's possible to stray off the route; you then have to call for revised directions. Or OnStar can give you compass directions to get back on course but not actual street names and turns. Also, if your GM car has traditional in-dash navigation, OnStar Turn-By-Turn can't link to it. That's an obvious and needed enhancement. OnStar is working on it, but gives no date for when it will be available. I think most people will be satisfied with Turn-By-Turn once OnStar gets the bugs out, but some will want both kinds of navigation, and they'll want the two interconnected.

Key-85? No, E85

GM is big on alternative fuels, particularly E85, the 85-percent-ethanol, 15-percent-gasoline blend that many of its cars use. When I asked operators about locations near the New York Thruway for purchasing E85 fuel, though, they seemed baffled. On my second try, I got a supervisor who, after several minutes of research, said she couldn't find any gas stations called "Key-85." Finally, on my third try, I got an acknowledgement that New York State has just two E85 stations, and an offer to e-mail me a link to all current E85 stations nationwide.

To its credit, Turn-by-Turn operators did find my home address, PC Magazine's address, the Pepsi Center in Albany (it's hard to miss, not unlike the Caddy I was driving), the Olympic ice arena in downtown Lake Placid, and a "Baptist church on Staten Island, N.Y." for which I deliberately left out the full name. That's OnStar at its best, both traditional OnStar Directions & Connections (the operator reads directions as you go) and OnStar Turn-By-Turn. If you know sort of where you're going and you get the city or town right, and the destination is urban or suburban, OnStar can tell you exactly where to go.

TBT rollout through 2007

GM is rolling out the Turn-By-Turn service to its cars lines, about 1 million total of the 4 million it builds in a year, from now through the end of 2007. Currently the service is available in the Cadillac DTS; its mechanical twin, the Buick Lucerne; and the Cadillac STS. If your 2007 GM car doesn't come equipped with TBT, you can probably have it added or activated fairly easily.

Actually, some GM cars, going back to about 2003, also can be retrofitted with up-to-date OnStar. There will be two kinds of retrofits: One is quick, easy, and affordable (other than the monthly service cost) and gives you Turn-By-Turn. The other will be necessary if you have a really old, analog-only OnStar system: It would give you digital OnStar but not OnStar Turn-By-Turn. The analog-only network goes dark around 2008, and if you don't upgrade by taking a three-year contract (in which case GM pops for the cost of the new equipment), you won't have OnStar service. That's going to be the case with other older (non-GM) cars offering first-generation telematics services.

Other Downsides

One other thing to know about OnStar: If you decide not to continue the service, OnStar disables the crash notification feature. It doesn't have to, but it does. Some other automakers keep emergency crash notification active even if you stop paying for the telematics-assist services they offer. (As required for any cell phone, the OnStar service has to be able to let you dial 911 manually, whether you've paid your bill or not.) I understand why GM does this: OnStar is a recurring revenue stream. If you get one of the key features for free, that's one less reason to re-up. Even so, it's still troublesome that GM deactivates a potentially lifesaving feature.

A minor, non-life-threatening annoyance, for me: When you're on hold—and with OnStar you can be on hold a lot—you will hear, interspersed with the be-right-back recordings, repeating house advertisements for OnStar touting its reliability, efficiency, and usefulness. OnStar says there is no way to opt out.

Better Luck Next Time?

I'll try to drive Turn-By-Turn again in a few months and report on improvements. This is too promising a service to give up on. It will likely cost about $10 a month beyond basic OnStar, but since OnStar Turn-By-Turn is free for the first year, and the first cars got it this past spring, GM hasn't seen fit to tell buyers what they'll be paying for OnStar Turn-By-Turn come 2007.

My belief is that Turn-By-Turn has to cost $10 a month in addition to the basic OnStar charge, because that's the going rate for competing navigation services, particularly the cell-phone navigation packages. Currently OnStar is $200 a year for the basic Safe & Sound package of remote door unlock, emergency notification, vehicle diagnostics (uploaded to your dealership and also sent to you as free e-mails), and stolen vehicle tracking (but no navigation help). The Directions & Connections package, $400 a year, adds operator-assisted navigation instructions, where the operator actually stays on the line with you during trips (short ones, at least). Most likely the Turn-By-Turn service will come in around $300 a year, because it involves less operator-assist time each month, though it's possible GM could just stick to $400 a year.

Like most technology, TBT, Version 1.0 needs improvement. And if General Motors is going to survive, the company needs to hit home runs with its cars and services. OnStar has that promise, and some facets are unique or best-in-class, such as the diagnostic uploads and the operator lookup, direction download service. Right now, though, the best you can say is that OnStar's glass is half full.