Saturday, June 23, 2007

Wilshire Monorail?

A monorail along Wilshire Boulevard has been suggested as a faster and cheaper alternative to extending the Purple Line "Subway to the Sea". Here are some considerations to evaluate whether a monorail could fit.

This image of the Las Vegas Monorail superimposed onto Wilshire in West Los Angeles shows the visual bulk of its concrete beams and columns, and how it blocks the left turn lane.

Las Vegas has the only transit monorail in the United States, begun construction in 2001 and opened in 2004. Its 2000 construction cost was $100 million/mile ($385 million for 3.8 miles; source). This was similar to elevated light rail, and about one-third the cost of subway construction. It would be more now, with construction cost inflation.

Las Vegas uses a proprietary Bombardier (Canada) design based on Walt Disney World. Hitachi (Japan), the world's other main monorail vendor, uses a different, incompatible, design. It's risky to be dependent on a single vendor.

Spans for the Las Vegas beams average 100 feet, with the longest about 120 feet. They are 26 inches wide and vary from 5 to 7 feet deep. The typical column is 56 inches by 32 inches (source). They likely would be larger in Los Angeles to meet our seismic requirements.

Aerial stations are quite large, cantilevered over the street with pedestrian bridges to the sidewalk, needing space for stairs, handicapped-accessible elevators, and possibly escalators (which tend to break in the weather). Is this acceptable on Wilshire?

Passengers would experience a 10-15 minute delay at Western Avenue, to transfer between aerial and subway stations and wait for another train.

What are alternatives to losing the left turn lane to columns? Las Vegas' 120-foot maximum span is far short of this typical boulevard intersection at Wilshire and Bundy, where it would take a 550 foot span across the left-turn lanes and cross street.

Even this massive bridge of the Green Line over Aviation and Rosecrans in the South Bay is only just over 300 feet.

The other possibility is "straddle bents" spanning the entire boulevard, like these three supporting a curve in Las Vegas. These would also be used if the beam curved to the edge of the boulevard if stations were built in buildings' upper floors.

For more perspectives see The Monorail Society and Light Rail Now.

(I plan a future post about monorails along freeways.)

4 comments:

K. M. Johnson said...

I'm fairly certain that Seattle has a monorail as well. It's short and mostly for tourists, but it does move people.

Anonymous said...

Yeah, although small, Miami does have one too.
I also heard about a proposal for a monorail along the LA River that Ray Bradbury submitted, I believe, in the early 60's. Seriously.

Scott said...

Miami does not have a monorail.

They have two systems. Metrorail is an elevated heavy rail train with third rail power supply. Similar to much of the BART system in San Francisco. Miami could not build a subway due to high ground water in all of Southern Florida.

The other system is the "Metromover." Not technically a monorail. Another elevated train, which I believe runs on rubber tires in single cars. The system runs on three different interlocking loops in the downtown area. The cars, tracks and elevated structures are smaller than the usual monorail or elevated heavy rail setup. It does go inside buildings in a few places.
Not really a monorail, more of a
"peoplemover".

Tiki said...

Seattle has a monorail that was built for the World's Fair during the 60's. A recent bid to expand it was killed permanently a few years ago.

I don't see the problem with running a monorail down the middle of Wilshire. For the most part, there's really not a lot to look at, so I'm not sure what people mean when they talk about "obstructed views".

Monorails have been running in Japan for quite a long time and have proven to be efficient and resilient in the face of earthquakes and we know Japan has it's share of nasty ones.

Another advantage I see in monorails is that of safety, especially when compared to at-grade light rail. Just the fact that the train is removed from the street surface removes the chance of collisions with vehicles or people.

Subways would seem to be the way to go from an overall standpoint but they are so expensive that it takes much longer for a community to summon up the cash and political backbone to push them into construction.

I don't dislike light rail or subways but I think it would be nice to see monorails get a fair shake when transit options are discussed. People are understandably wary of monorail technology but then people in L.A. are wary (afraid?) of nearly any kind of transit that the city decides to build. Those of us Angelenos who haven't experienced the speed and efficiency of rapid transit tend to look at the idea with a weathered eye. It seems we just need to get used to the idea to make it happen.

L.A. won't be a world-class city until it can integrate its neighborhoods with fast, efficient transit.