THIS city's grand experiment in altering its driving habits in the wake of the earthquake is producing important changes but not the fundamental shifts in transportation patterns that some had hoped for.
True, more Angelenos are boarding trains, riding buses, and even making the ultimate southern Californian sacrifice - carpooling. But the numbers have tailed off since immediately after the temblor, and concern is rising among some experts that residents will return to their old ways, driving solo, as soon as fractured freeways are fixed.
As much as anything, the earthquake has spurred a rethinking of what should be done about L.A.'s transportation system.
Some argue that the quake reveals the importance of pushing ahead with the massive rail network already being built, one of the most expensive public-works projects in United States history.
Others want resources diverted to rebuilding the region's all-important highway system. Still others see the lesson somewhere in between: the need to move forward with a broad range of transportation alternatives.
``Ultimately, what I think will come out of it is a resolve to provide greater capacity in alternative modes'' of all kinds, says David Stein, a transportation planner with the Southern California Association of Governments.
That more-sweeping changes haven't been wrought by the earthquake is perhaps understandable. For one thing, the 6.8-magnitude temblor damaged but did not destroy the region's highway system. Four major thoroughfares were affected.
Since then, transportation officials have set up detours around most major choke points, though that doesn't mean people have not been inconvenienced.
Immediately after the quake, many drivers felt like they were measuring their commutes in geologic time. Even though the driving times have improved markedly since then, some still aren't sure whether to grab a briefcase or a toothbrush when they leave for work.
There is also only a limited number of alternatives. The region's major long distance commuter rail, Metrolink, is only 15 months old and still growing. It has four lines, two of which parallel highway routes damaged in the quake. These have proven invaluable to many commuters in those areas.
But people still have to get to and from the train stations, and there are only a limited number of people who work near where the lines make stops. The same goes, to a lesser extent, for the routes serviced by buses.
Finally, there is the region's legendary cultural affinity for the automobile. This isn't a city as much as an outdoor auto museum.
Yet, even within these parameters, subtle but significant changes have occurred in the month since the quake:
* Trains. About 20,000 riders are now taking Metrolink trains a day - double the number before the earthquake. Immediately after the temblor, ridership on one line increased more than 20-fold.
Long term, rail officials say they will be ``happy'' if they retain a 10 percent increase in ridership. The city's nascent subway system, of which only 4.4 miles have been completed downtown so far, has seen a jump from 14,000 riders to 17,000.
* Buses. Bus use is up 8 percent - or about 80,000 riders a day - out of a total of 1.2 million passengers.
* Carpooling. Calls coming into a local hotline that matches riders have gone up from 286 a day to over 400. An estimated 16 percent of Los Angeles's commuters carpool - the highest rate of any major US city.
Still, that means more than 80 percent drive to work alone, and, given the congestion and pollution that habit creates, the attempts to reinvent the region's transportation system will go on.
Some want to press on with building a network of subways, light rails, and other trains that is expected to cover more than 450 miles over the next 30 years. Estimated cost: as much as $163 billion. Others, however, say that is too much to put into a rail system in such a low-density region. They would rather see some of the money spent on expanding the bus system or highways.
Other ideas surfacing to wean Angelenos from their cars: charging commuters a fee for driving during rush hour; erecting toll ways; eliminating free parking.
``Auto dependency is real,'' says James Moore, an urban planner at the University of Southern California. ``When you ask people to give up their cars, you are asking them to change the quality of their lives.''