While obiously not on the scale you are talking about, some street space in critical areas is being carved out from car traffic.

Per Streetsblog LA, 2021 saw the following new bus-only lanes open:

• 1.2 miles two-ways on Alvarado Street in Westlake/MacArthur Park
• 1.3 miles one-way on Grand Avenue in downtown L.A.
• 1 mile one-way on Olive Street in downtown L.A.
• New bus lane red pavement markings in West L.A. and downtown L.A.
• Also in 2021, Culver City installed 1.3 miles of two-way bus lanes as part of its MOVE Culver City project, which also included pedestrian and cyclist improvements.

Click the link for additional links to the listed projects.

Clearly we need more, but it's a start.

If I were in charge, I would probably end the Purple Line at La Brea and refocus transit dollars on a subway line to East LA and El Monte.

I guess that's why I'm not in charge haha and exiled in the Pacific Northwest.

Yeah, that's a terrible idea. Ridership on the D Line (formerly Purple) into the Westside will absolutely justify the expense of the extension, and will exceed anything we could reasonably expect to generate by expanding into East LA/El Monte instead.

Downtown Beverly Hills is a major destination, with its touristy shopping district, and merits a heavy rail connection. So does Century City, with its 50,000 office workers. And then there's Westwood, where office and residential towers line Wilshire--not to mention UCLA, which not only has some 45,000 students, but is also Los Angeles' fifth largest employer with some 42,000 jobs. Trust me, parking at UCLA is one of the circles of hell.

Build it and they will come.

I do wonder if a sort of linear downtown or "Manhattanization" could happen along the Wilshire Corridor where the Purple Line is being extended under. Pretty soon LA and other communities will be forced by the HCD to accommodate hundreds of thousands of new housing units, which could logically be handled by upzoning around new Purple Line stations.

Densification is almost certainly on the table, but 'Manhattanization,' as in a thicket of skyscrapers? I don't know. I can easily see a gradual increase in the number of skyscrapers in Century City, and an even faster upzoning in Mid-Wilshire/Miracle Mile, but I wouldn't expect a lot of new skyscrapers in Beverly Hills or Westwood proper (both of which are currently underserved and merit heavy rail as they exist today). I can definitely imagine some significant highrise development in the vicinity of the big VA Hospital campus--that's a strangely underdeveloped corner of town.

Not to mention universities have a lot of visitors for conferences and workshops. Most of the time I'm in LA I'm either going to UCLA or Caltech.

There are no stats, although I did mention ridership density for Crenshaw North being in the 10,000+ range. At-grade LRT works for geographically smaller cities with significantly smaller populations, Calgary being a great example.

For core LA, at-grade LRT is not a viable alternative for the simple fact that most arterials aren’t wide enough. And even if you were yo have street-running rail, think about how slow and unreliable it would be. It only takes one idiot driver to ruin the commutes of hundreds of thousands of people.

The difference between HRT and LRT is grade-separation, frequency, and capacity, not the rolling stock itself.

Manila:

• Video Link

That's simply not true. LRT can be grade separated and even underground like a subway, case in point the first LRT in North America, in Edmonton:
https://upload.wikimedia.org/wikiped...cember2019.jpg
https://en.wikipedia.org/wiki/Bay/En...cember2019.jpg

These trains have greater frequencies than LA's D/Purple Line heavy rail subway (5 min peak vs LA's 10 min peak). Edmonton's LRT carries about 115,000 people per day compared with 135,000 on the LA Purple Line - not far off.

The difference between HRT and LRT absolutely is rolling stock (which is how it has higher capacity more easily), but not grade separation or frequency. You're confusing LRT with streetcars, which none of the LRT lines in LA are. All of LA's rail lines are separated from traffic, even if surface level LRT, allowing for speeds not much slower than max HRT speeds (which they rarely get to anyway). Meanwhile portions of HRT in other cities (like Toronto and Atlanta) are not sub-surface. Others still are above ground (as in Chicago, New York, Atlanta, and Vancouver), which is something that LRT has been shown to do as well (as seen in Vancouver, Calgary, and Edmonton).

You could easily build an extension of the L/Gold Line underground through DTLA and then down Avalon through South Central, also underground (or elevated). It would be LRT still but have similar grade separation to traditional HRT systems.

Why would they bother to grade separate a light rail system?

Light rail is often grade separated for speed, reliability, train length... It allows trains to operate like heavy rail in some ways but still cross streets sometimes.

No, it’s really not. That’s a very US-centric view of what’s heavy rail/rapid transit. You yourself brought up Paris Metro’s (one of the best in the world) mostly narrow-body trains — they’re even narrower than LA’s LRVs, which are about the same width as the NYC Subway’s A Division rolling stock. London Underground and Madrid Metro also have trains with narrower profiles, with the latter running on overhead catenary lines. Capacity comes from greater frequency, which is made possible by grade-separation in areas with lots of vehicular traffic.

LA's Kinkisharyo P3010s, which will eventually constitute the bulk of the LRT fleet, feel quite spacious inside. And this is without bench-style seating.

https://lbpost.com/wp-content/upload...6/DSC_0557.JPG
https://lbpost.com/news/place/public...ars-of-service

Absolutely agreed. Isn't this obvious, especially in terms of speed? LA's C-Line, which provided over 30,000 trips daily before the pandemic, is a fully grade separated light rail line and, unsurprisingly, is the region's fastest ride. Per wikipedia, a typical C-Line consist tops out at speeds of 65 mph and "takes only 34 minutes to travel its 19.5-mile (31 km) length, at an average speed of 34.4 mph over its length."

Yeah, the C Line is actually faster than all of Washington Metro's heavy rail lines. Only reason why its not a light metro yet is because ridership doesn't require it to have very low frequencies.

To do the same things that HRT does but for less money. Do people in HRT-centric cities like New York really think that every LRT system is basically a streetcar??

You're conflating HRT with rapid transit more broadly. Yes, HRT is rapid transit, but so is LRT. They both function similarly in their respective cities, LRT is just relatively newer technology and tends to be built in smaller and/or newer cities, like San Diego, Portland, and Ottawa.

This just further proves the greater overlap in abilities between HRVs and LRVs.

And yet, you conveniently ignore a stat in which an LRT system beats LA's heavy rail for frequency. Even within LA people subsequently have pointed out the C Line, an LRT line, is faster than all of LA's other lines, and all of the DC metro lines.

And tell me, if both LRT and HRT are grade-separated, how is that specifically contributing to greater frequency (which I've already debunked anyway)?

In terms of speed, the DART LRT runs at an average of 30 miles (48km) per hour while New York's HRT subway runs at an average of 17 miles (27km) per hour and Chicago's L has an average of 23 (37km) miles per hour.

So what exactly is your point about rolling stock vis-a-vis capacity? How does it represent a fundamental difference between "HRT" and "LRT" if some LRVs are wider than some of the HRVs running on three of the world's top 10 metro systems and LRT lines having the capacity to draw the same ridership as HRT lines?

You said the following:

Does that mean BART is more of a HRT system than the Paris Metro?

As for frequency, LA's two "HRT" lines are limited to 4-minute headways because they interline between Union Station and Wilshire/Vermont. More to the point, frequency/headways and ridership are correlational, not causal. And ridership is not a reflection of capacity, but rather more locally specific factors such as the nature of the corridor itself, demand, quality of service, overall transit appetite, etc.

You're painting with a very broad brush and totally ignoring important physical, cultural, and logistical differences.

The rolling stock used in HRT and LRT is generally different. You said:

Light rail vehicles and heavy rail vehicles are different. Yes, some HRT vehicles are narrower, but generally speaking, they have higher capacity per train car, and the technology is different (for one thing, it's much older).

We've already disputed your claims of grade-separation and frequency being the distinction. LRT is generally in a dedicated right of way not unlike HRT. Frequencies can be greater and trains can run faster than HRT systems (not exclusively - merely it can happen).

So what's left? The rolling stock and how that functions in terms of station design and so forth. If anyone is ignoring anything, it's you - myself and others have clearly destroyed your points and yet you still latch onto your same talking points.

Grade separation of a bus or rail corridor (including light rail or commuter rail) is to allow for increased capacity of the corridor, either increased frequency or longer vehicles or both, without that service interfering too much with the regular road traffic, either auto or pedestrians or bikes.

With light rail and commuter rail, there is also the option to combine vehicles and cars into trains to increase the headway (reduce the frequency of service), and so reduce the disruption to other traffic, or the reduce the disruption other traffic causes to the transit service.

Sometimes you will find a bus or rail crossing is grade-separated because the bus and rail service is too busy, but given the low ridership of many systems, it is because the road is too busy with cars, trucks, bikes, and/or pedestrians.

Around 10-minute frequency in each direction with trains of LRVs is good capacity. Signal priority can be applied without much disruption to other traffic. Each LRV is probably around 30m (100ft) long, so each train 60m long. But if ridership increases too much, maybe higher frequencies and/or 90m or 120m trains would be needed, and so the disruption to other traffic could be too much, and that is when grade separation is needed.

The ability to combine vehicles into trains is the main advantage of light rail vs. bus rapid transit. Articulated buses are usually only 18m (60ft) max, only 50% longer than regular buses. The capacity of BRT is less than 1/3 of light rail with 2-car trains for a given frequency. So when we talk about BRT vs. LRT, it's really a question of the capacity needed. And of course, capacity is exactly what defines heavy rail as well. High frequencies and long trains? You need grade separation for that, and that is what makes a rail line heavy rather than light, or full rapid transit. Light rail and bus rapid transit therefore can be considered as semi-rapid transit, having some features of rapid transit (all-door boarding, limited stops, exclusive ROW, grade-separation) but not all because the ridership doesn't require it, the extra capacity is not needed yet.

Capacity is why Ottawa needed to replace its grade-separated BRT with rail. The problem wasn't lack of ridership, it was too much ridership. Ottawa is one of the leaders in transit ridership, and the articulated buses could no longer handle it. The difficulty of articulated buses to operate in snow only made matters worse. Similar problem could be seen in Mississauga, with buses coming by every 3 minutes in each direction in one corridor, but buses still too full and sometimes not being able to stop and having to leave the riders stranded and continue waiting. The fact that articulated buses had to be left in the garage during periods of heavy snowfall. So the service needed to be replaced with LRT, which is now under construction.

The question with Los Angeles or any US system is whether their problem is too much ridership, or is it not enough ridership? Which bus corridors are becoming so crowded that they need to replaced with light rail? Which light rail corridors are becoming so crowded that they need grade separation to allow for longer and more frequent trains? That is all any city needs to think about when considering building new rail or upgrading existing rail. Canadian systems are building new rail but not because of lack of ridership, and maybe the USA needs to taking that same approach more.

What’s the fundamental difference between the two technologies? That’s not a rhetorical question… I really want to know. What extra “equipment” does an EMU have underneath and/or on top (if running on pantographs) that an LRV doesn’t?

A single LRV, at least in LA’s case, is longer (90 feet) than an HRV (75 feet, which is actually longer than most HRVs around the world) and can accommodate as many, if not more passengers. It also is “heavier” by actual weight.

HRT trains have higher capacity because as a service they tend to operate in consists of 5-10 cars — depending on the length of the individual vehicle.

HRT is ultimately about the service, not the vehicles; to me, HRT = rapid transit. As long as it’s 100% grade-separated, can accommodate around 30,000 riders per hour, and is powered by electricity, then it’s a rapid transit (HRT) line. A 900-foot, 10-car LRV train (in theory) that’s fully grade-separated train and has 4-minute headways during rush hour wouldn’t be heavy rail? Yet Cleveland’s Red Line would be?

Fully grade-separated, high-frequency trains are considered metro lines, regardless of technology — see Manila (which you ignored) and Vienna U-Bahn’s U6.

When I made the comment about grade-separation and frequency, I was thinking specifically of LA’s needs. You can’t have surface-level trains crossing a busy intersection like Santa Monica/La Brea every 2 minutes during rush hour without creating huge bottlenecks. Grade-separation avoids that problem.

Reading between the lines, when I said that LA needs more HRT lines, I didn’t necessarily exclude LRT trains running in subway configuration. But LA’s LRT lines are limited to 270-foot trains, and as mentioned, it only takes one idiot driver along the at-grade portion to disrupt service across the entire line.

It is mostly straight and has long distances between all of its stations. I seem to recall that the elevated section near Rodondo Beach ran quite a bit slower than the section in the middle of the freeway.

No matter - the green line is a total anomaly. It's a tertiary, ultra-low priority line that by an accident of history was built very early in the network's development.

The LA heavy rail subway has close stations and several curves below downtown LA that require relatively slow operation. The red line has two 90 degree curves outside of downtown. The purple line won't have any sharp curves outside of the shared downtown section, meaning the new Wilshire Blvd line might have a higher average speed than the existing red line outside of downtown.