Battle of the 2016 Transit Measure Expansions: Measure M (LA) vs. Sound Transit 3 (Seattle) (live, America)

[CrazyDonkey]

L.A. backed itself into a corner by building freeways. Seattle backed itself into a corner by not building freeways.

[2Easy]

Originally Posted by CrazyDonkey

L.A. backed itself into a corner by building freeways. Seattle backed itself into a corner by not building freeways.

Yet somehow Seattle actually has many more freeway miles per capita tha Los Angeles.

Highway & Motorway Fact Book: Index

[CrazyDonkey]

Originally Posted by 2Easy

Yet somehow Seattle actually has many more freeway miles per capita tha Los Angeles.

Highway & Motorway Fact Book: Index

That shows the effect of sprawl. Freeways, because they are free, are population multipliers. The more you build, the MORE you need to build.

Seattle is geographically constrained.

Seattle: 83.87 sq-mi
L.A.: 468.74 sq-mi

[Vincent_Adultman]

Originally Posted by CrazyDonkey

Sound Transit's is a hybrid system, running 1500 VDC traction electrificaion, twice that of most light rail systems (750 DC)

Great point.

[Vincent_Adultman]

Originally Posted by CrazyDonkey

That shows the effect of sprawl. Freeways, because they are free, are population multipliers. The more you build, the MORE you need to build.

Seattle is geographically constrained.

Seattle: 83.87 sq-mi
L.A.: 468.74 sq-mi

To be fair, here’s a more complete map of Seattle’s highway system (since the LA one shows the full region).



http://us-atlas.com/images/132%20seat.jpg?crc=347671748

[2Easy]

Originally Posted by CrazyDonkey

That shows the effect of sprawl. Freeways, because they are free, are population multipliers. The more you build, the MORE you need to build.

Seattle is geographically constrained.

Seattle: 83.87 sq-mi
L.A.: 468.74 sq-mi

I’m talking Metro not city limits. If Seattle is constrained and sprawl leads to more freeways, shouldn’t Seattle have fewer freeway miles than LA?

[2Easy]

Originally Posted by Vincent_Adultman

Great point.

Is it? Most light rail is 750V. The NYC subway is 600V. The DC metro is 750V. Seattle is 1,500V. What does that mean for operations? What advantage does that give Seattle? It’s unclear to me.

[Vincent_Adultman]

Originally Posted by 2Easy

Is it? Most light rail is 750V. The NYC subway is 600V. The DC metro is 750V. Seattle is 1,500V. What does that mean for operations? What advantage does that give Seattle? It’s unclear to me.

I looked into it and you're right - all that does is reduce the number of electrical substations, which has little impact on operations.

But I think the main thing that makes Seattle light rail more similar to heavy rail or at least light metro is the grade separation. That allows for 4 car trains and higher frequencies. The MLK at-grade section is the unfortunate segment that sticks out like a sore thumb and it will reduce peak headways from potentially every 90 seconds to every 3-4 minutes.

[2Easy]

Originally Posted by Vincent_Adultman

I looked into it and you're right - all that does is reduce the number of electrical substations, which has little impact on operations.

But I think the main thing that makes Seattle light rail more similar to heavy rail or at least light metro is the grade separation. That allows for 4 car trains and higher frequencies. The MLK at-grade section is the unfortunate segment that sticks out like a sore thumb and it will reduce peak headways from potentially every 90 seconds to every 3-4 minutes.

Reducing the amount of substations may still be a good thing. In LA we have enough substations to run 270 ft lrv’s every 3-5 min in both directions. But I think that we’re maxed out. To run 360 ft trains like Seattle we’d have to add 25% more substations. Maybe Seattle added that capacity for less money. I don’t know.

[Vincent_Adultman]

Here is a better map of the fully funded Seattle build out that's part of Sound Transit 3:



https://78.media.tumblr.com/5d04af8f...c4oo1_1280.jpg