search the site
 daily menu » rate the banner | guess the city | one on oneforums map | privacy policy | DMCA | news magazine | posting guidelines

Go Back   SkyscraperCity > Infrastructure and Mobility Forums > Highways & Autobahns

Highways & Autobahns All about automobility



Global Announcement

As a general reminder, please respect others and respect copyrights. Go here to familiarize yourself with our posting policy.


Reply

 
Thread Tools
Old November 23rd, 2017, 02:58 PM   #12441
sotonsi
Registered User
 
Join Date: Feb 2007
Posts: 5,465

Quote:
Originally Posted by SounderBruce View Post
A perfect depiction of induced demand.
Or, much more likely, suppressed demand becoming unsuppressed - the extra capacity hasn't created more demand, but rather supplied more of it.

This isn't new demand (which is created by new routes opening up or developments on existing routes) that's induced by the increase in capacity, but demand that was already there and unfulfilled due to not enough capacity before the widening.

Adding more capacity somewhere where demand is saturated means more people can make that journey at a similar level of congestion. Congestion is self-regulating and no one wants to sit in traffic or be rammed up against several strangers on transit if they can help it.

Inner London's traffic speeds haven't changed for decades - with the increase of private cars and the building of new roads about 50 years ago they didn't change, and with the pushing people out of space-taking cars and onto buses and bikes of the last 15 years, they didn't change either. The saturation of supply by the demand means the system is at equilibrium when it comes to speed. The same is true of the Sepulveda corridor where any capacity increase or efficiency in using that capacity will just fill up to reach the point of equilibrium.
Quote:
"The 405" (bleh) just got expanded at the cost of $1 billion and really doesn't look any different during peak periods.
But a whole other lane of traffic can now travel instead of not travelling. If you are going to spend $1 billion dollars on something, you'd better be doing something that is utilised by people.

When new transit schemes get busy due to people using them, that's (rightly) treated as a success.
When new road schemes get busy due to people using them, that's (wrongly) treated as a failure.
Quote:
The Sepulveda Pass Metro line can't come soon enough.
Absolutely, for the exact same reasons as to why widening the 405 meant it filled up - it's a corridor without anywhere near enough capacity for the demand. Adding other modes is a good thing, but too many people see transit and roads as either/or not both/and.
sotonsi no está en línea   Reply With Quote

Sponsored Links
Old November 23rd, 2017, 03:12 PM   #12442
sonysnob
Registered User
 
Join Date: Dec 2004
Location: North York
Posts: 916
Likes (Received): 798

Quote:
Originally Posted by SounderBruce View Post
A perfect depiction of induced demand. "The 405" (bleh) just got expanded at the cost of $1 billion and really doesn't look any different during peak periods.

The Sepulveda Pass Metro line can't come soon enough.
Holiday weekend traffic isn't really an example of induced demand.

Los Angeles County has a pretty significant amount of transportation demand management measures in place. These measures include carpool lanes, tolled express lanes, and a growing light rail network. Transportation demand management works on the assumption that not everyone needs to use the highway network at the same time. It's somewhat analogous to how a bank can lend out more money than it has deposited. A bank can do so on the assumption that not everyone will need access to their money at one time.

The problem with holidays is that lots of people do need access to the highway network at once (or at least want access to the highway network badly enough to be willing to endure the experience). They are making trips that aren't within their typical daily routine, and the TDM measures that try to manage highway capacity aren't very useful.
__________________
Asphaltplanet.ca
sonysnob no está en línea   Reply With Quote
Old November 23rd, 2017, 03:24 PM   #12443
ChrisZwolle
Road user
 
ChrisZwolle's Avatar
 
Join Date: May 2006
Location: Zwolle
Posts: 43,110
Likes (Received): 18676

They should've built four or even six tolled express lanes across the Sepulveda Pass. Not just an overpriced family lane.
ChrisZwolle no está en línea   Reply With Quote
Old November 23rd, 2017, 05:08 PM   #12444
sonysnob
Registered User
 
Join Date: Dec 2004
Location: North York
Posts: 916
Likes (Received): 798

Quote:
Originally Posted by ChrisZwolle View Post
They should've built four or even six tolled express lanes across the Sepulveda Pass. Not just an overpriced family lane.
^ I agree. The 405 would be a fantastic facility for an express tolled facility. A four lane tolled facility was considered during the design, however from what I found online, it was always proposed to be a four-lane elevated tollway running through the median. Presumably, what ended up being designed didn't preclude such a tollway in the future.

See Alternative 4 and 5 on page 33 of the below report:
http://www.dot.ca.gov/d7/env-docs/do...ass_IR_EIS.pdf
__________________
Asphaltplanet.ca
sonysnob no está en línea   Reply With Quote
Old November 23rd, 2017, 09:38 PM   #12445
jchernin
Registered User
 
jchernin's Avatar
 
Join Date: Jul 2005
Location: Santa Rosa/North Bay
Posts: 507
Likes (Received): 533

Quote:
Originally Posted by sotonsi View Post
Adding other modes is a good thing, but too many people see transit and roads as either/or not both/and.
Couldn’t agree more. We need both.

Transit gives us an option to driving. Something that is extremely important. If there’s an accident on the 405, right now you’re screwed, along with tens of thousands of other people. But with a transit line, there’s at least another option.

Up here in Wine Country after the fires, this transit option has played a critical role in the disaster. Our recently opened train line (SMART) provided free emergency service immediately after and continues to give people options now that traffic here has significantly worsened due to the fact that 1000’s who have lost their homes now live further away and are on the freeway more. My wife’s evening commute has gone from 40 minutes to 1 hour and 15 min on Tuesday (she took SMART the next day).

Back to topic..

Yes, we need freeways and they need to be expanded wisely. We also need to invest heavily in transit options. As one the busiest freeways in the country, the 405 could probably benefit from a tolled facility. There’s still a good chance though that you’ll encounter traffic somewhere along your route. So a rapid transit line is needed there ASAP. Right now, people have one option, and that is sitting in traffic. The more options the better.

I’ve always wondered what our cities would/will look like with teleportation when all this infrastructure isn’t needed.
jchernin no está en línea   Reply With Quote
Old November 23rd, 2017, 09:52 PM   #12446
ChrisZwolle
Road user
 
ChrisZwolle's Avatar
 
Join Date: May 2006
Location: Zwolle
Posts: 43,110
Likes (Received): 18676

Apart from converting left shoulders into carpool lanes, there hasn't been much freeway upgrades in the Los Angeles area since the last freeways opened during the 1970s. The population has grown by 7-9 milion people since. Think of adding the population of the Dallas-Fort Worth area to an already overburdened road system. It's no wonder you see traffic counts around 300,000 on just 10 lanes with congestion occurring 10-12 hours per day. It's clear that a single carpool lane - even if it costs $ 1 billion - wouldn't significantly alleviate congestion. However Los Angeles has spent billions on rail that has not alleviated congestion either. Reportedly the transit share is even lower today than it was before the rail transit system was built, due to massive cuts to bus services.
ChrisZwolle no está en línea   Reply With Quote


Reply

Tags
america, california, highway, highways, interstate, los angeles, united states, urban

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Related topics on SkyscraperCity


All times are GMT +2. The time now is 09:29 AM.


Powered by vBulletin® Version 3.8.11 Beta 4
Copyright ©2000 - 2017, vBulletin Solutions Inc.
Feedback Buttons provided by Advanced Post Thanks / Like (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.

SkyscraperCity ☆ In Urbanity We trust ☆ about us | privacy policy | DMCA policy

Hosted by Blacksun, dedicated to this site too!
Forum server management by DaiTengu