The Metro Rail/Subway system is not heavily used all the time like New York. However, there are peak periods where it has considerable ridership, which I think was its intent. The idea is that you want these mass transit options to alleviate stress during rush hour periods primarily; that is where they prove their worth. The Red Line can be quite full during peak periods in the morning commute. Also, I've seen new high density housing developments along Western that could feed to the Hollywood/Western station (including one on top of the station) and IIRC, there is the proposed development at Universial City Walk.

I expect the Gold Line to be more used once that East LA extension goes up. Does anybody have current stats on its daily avg and peak hourly ridership though?

It will take time for people to change their habits. If gas prices in LA continue at $3+ over the summer, I would expect ridership to go up and hopefully some permanent converts.

One thing is true, LA city can't build any new roads or highways.

I will use Downtown LA as an example. This is a bottle neck for anyone trying to between the northwest and southeast parts of LA county. A lot of problems in downtown could be solved if you could tear down the 101, 110, and 5 sections in that area; they are ancient and poorly designed. Trust me, I've spent 20 minutes just to get from Union Station to Vermont, which is only a few miles.

But unless the next major earthquake forces the issue, it just can't happen. So what are the other options for LA? You can't really add HOV lane. You could build some sort of skylane bypass or HOV, but that won't be cheap or easy either and could also easily turn into a construction fiasco on the scale of the Red Line or Bay Bridge. As it is currently, the current roads in LA City are badly in need of repaving. I can think of plenty of streets with breaks and cracks; heck, they couldn't even get all the potholes repaired until the mayor made that hotline.

As for buses, have you ever actually ridden a 720 down Wilshire. Those things are PACKED... like worse than sardines packed... during rush hour. And its still prone to slowdowns in traffic like Wilshire east of UCLA as it approaches Sunset, Wilshire between Wilton and Western to name a few. Even at high frequency they can still be pretty full. People are generally discouraged from using this when they can be stuck just as long in traffic, but in the comfort of their own vehicle. A subway would be infinitely more useful, but because of restrictions it will never happen, even if safer construction methods are developed. So... status quo and lost productivity for the next two decades until someone adds up the totals and realize that the amount lost was equal to construction costs of today... oops?

You're right, the subway/light rail is not right everywhere for the city of LA, but there are corridors where any alleviation during rush hour that does not interfere with surface traffic would be much more useful. Although it would be cool to have that grid, I don't know if it would be as effective for LA given its mentality.

But also, let's not confine ourselves to only recalling Metro's construction follies. Remember the I-105 had the same problem as Metro Red Line construction, just not as visible. From Wikipedia:

After construction began in the 1980s, failure to perform a full survey of the area's groundwater deposits, combined with the 20-30 foot below-grade trench through the city of Downey, resulted in buckling and cracking along the eastern portions of the route. At one point a large sinkhole opened in the Bellflower Boulevard onramp. This resulted in construction of an elaborate pump system along the freeway between the interchanges with I-710 and I-605.

I think LA's bigger problem was poor (and possibly corrupt) selection in construction companies leading to poor workmanship and costly overruns. I think most of those have been gone since the late 90's (I remember the 10 repairs after '94 going amazing well though)

I agree, more buses work well for much of LA county, but you can only put so many buses on the road before you need an alternative in the densest corridors. I think LA county would benefit a lot if it could get many of LA city's cars off the road, even if the direct benefits are not immediately evident.