Ask me about being a Traffic Engineer!

The Something Awful Forums > Discussion > Ask/Tell > Ask me about being a Traffic Engineer!

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Socket Ryanist: Aug 30, 2004

Bold Robot posted:

This might be apocryphal, but supposedly that whole quadrant of Berkeley is designed to be as difficult as possible to transit by car, in order to encourage people to take the main roads (MLK, California, etc.) instead of driving through neighborhoods. For those that don't know the area, a huge section of Berkeley is a tangled warren of awful roundabouts like the one quoted above and bizarre barriers that turn what could easily be through streets into a network of dead ends.

There's nothing bizarre or apocryphal about it. It's a very effective system that does a good job of keeping the minor streets relatively car-free, while still making them easy to navigate and traverse on foot or by bike (the roundabouts and diverters don't affect bicyclists).

If you are visiting that area of berkeley, the parking garages (which you should use, since street parking is very scarce) are on major roads anyway, and if you live there you should only have to drive when leaving town anyhow--it's a very walkable city.

Socket Ryanist fucked around with this message at 18:29 on Apr 26, 2011

# ¿ Apr 26, 2011 18:18

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# ¿ Apr 28, 2024 00:53

Socket Ryanist: Aug 30, 2004

It certainly wouldn't make sense on an intersection between a major street and a minor street, because through traffic on the major street would conflict with through traffic going the opposite direction.

# ¿ May 16, 2011 07:37

Socket Ryanist: Aug 30, 2004

I've been in some areas where 4-way stops are the norm and a lot of the time there is no "4-way" or "all-way" sign under the stop sign. Is this compliant?

# ¿ Jun 21, 2011 20:30

Socket Ryanist: Aug 30, 2004

California does this thing somewhat often--instead of a lane just exiting, the exit splits off and then the lane abruptly ends. There's no "exit only" sign for the right lane because technically the right lane isn't exit only... it just ends very abruptly immediately after the exit.

Is there any good reason for this?

# ¿ Aug 17, 2011 13:32

Socket Ryanist: Aug 30, 2004

What really annoys me about it is that there's no changing of the lane dashing to let you know that the lane is going bye-bye. It's rather startling.

# ¿ Aug 17, 2011 18:01

Socket Ryanist: Aug 30, 2004

The pavement on the street outside my house used to be a pretty good testament to the problem with using asphalt.

We're on a hill, and our building gets deliveries from large trucks about a dozen times a week. the last few yards of pavement right before the stop bar (going downhill) had some serious washboard action going until they redid it recently (I'm talking 2' high bumps).

# ¿ Oct 18, 2011 03:20

Socket Ryanist: Aug 30, 2004

I ate some tilapia earlier today and thought of this thread

# ¿ Oct 18, 2011 13:12

Socket Ryanist: Aug 30, 2004

Mandalay posted:

San Francisco is pretty proud about removing downtown highways, too.

It's great for San Francisco but sucks balls for people who want to drive between the east bay and the peninsula via the bay bridge. There's no way to bypass the clusterfuck of people getting on or off 101/80 in downtown SF

Maybe they could remove most of the exits/entrances except for one big one at each end.

# ¿ Nov 13, 2011 00:25

Socket Ryanist: Aug 30, 2004

grover posted:

Is it possible to develop the inside of a cloverleaf, like with parking lots or stores or whatever, with a tunnel to local roads that serve it? It often struck me as a lot of wasted space, especially in densely developed areas.

I've seen development inside loop ramps before but I don't know of any full cloverleafs that have been developed, probably because there are very few full cloverleafs in densely populated areas around here (actually, there are few full cloverleafs around here in general)

# ¿ Nov 16, 2011 15:20

Socket Ryanist: Aug 30, 2004

Chaos Motor posted:

Irrelevant, the officer was not a witness and is unable to verify any information. His testimony is hearsay and hearsay is not admissible.

Why does anyone have to testify? Aren't the photographs enough evidence? Surely a good enough set of photographic evidence is enough to convict people of SOME offenses?

# ¿ Apr 17, 2013 03:51

Socket Ryanist: Aug 30, 2004

Oh here's a question: Late at night I often see pedestrian signals do the countdown with flashing "don't walk", then when they hit zero they just go back to "walk". Obviously this is in the direction of the major street (which stays green until it's triggered), but why wouldn't it just stay on "don't walk" until someone hits the button?

# ¿ Apr 17, 2013 03:59

Socket Ryanist: Aug 30, 2004

Apologies if something similar has been posted before but:

I just moved to Santa Clara, Calif, and I live right off of El Camino Real. One thing that bugs the hell out of me is that this road--lined with stores, restaurants and bus stops as it is--has very few crosswalks. So here's an idea: if you have two intersections that are really far apart, why not add a controlled crosswalk halfway between them. Then the signals for each half of the crosswalk could be synchronized with the light down the road so that they turn green either simultaneously or in sequence. Sure, pedestrians have to cross the road in two halves, but I'd rather jaywalk across half of el camino than all of it.

A good example of what I'm talking about is the stretch of El Camino Real in Sunnyvale between Bernardo and Sylvan. Over a quarter mile between crosswalks, and they for some reason thought it was a good idea to put a bus stop smack dab in between them.

Socket Ryanist fucked around with this message at 21:53 on Jun 21, 2013

# ¿ Jun 21, 2013 21:49

Socket Ryanist: Aug 30, 2004

Jeoh posted:

Why not build a pedestrian bridge for a road that size?

No room for it, the businesses come right up to the sidewalk. Plus, it would be used by like maybe 10 people a day.

Plus, 50% of the time there's not enough traffic to justify a pedestrian bridge, and when there is it's moving so slowly that an extra crosswalk wouldn't really hurt it much.

Socket Ryanist fucked around with this message at 05:37 on Jun 22, 2013

# ¿ Jun 22, 2013 05:27

Socket Ryanist: Aug 30, 2004

So after living in santa clara county for a while I can't help but notice that our freeways are a nightmare but our expressways are actually not at all stressful to drive on.

Which makes me wonder: Is there a way you can implement controlled merging on an interstate without jeopardizing your federal funding? Like it seems like the most obvious way to solve these merging issues would be to install traffic lights that stay off until the road becomes congested. Ramp meters for onramps are allowed but to really solve the problem you would also need meters on the freeway itself.

# ¿ Jul 23, 2013 09:16

Socket Ryanist: Aug 30, 2004

Also, look at the strip of US 101 between the interchange with CA 85 and the dumbarton bridge. For context: there are a LOT of employers along this strip (lockheed martin, NASA, the military, facebook, stanford university, the list goes on) and many of their workers come from far away in every direction, the traffic jam in this area fucks up rush hour for all of santa clara and san mateo counties.

I'm not a traffic engineer, but it seems like a dumb idea that the 85-101 merge is immediately followed by FOUR offramps in the space of one mile. I can see they fixed the shoreline blvd exit to make this a bit less painful, but if you look at google's traffic data that merge backs traffic up down 85 and 101 for quite a distance.

Central Expressway is under-utilized, not only because it comes to an unceremonious end at san antonio rd, but also because there's no easy way to get onto it from northbound 85 (look at that interchange, isn't it ridiculous?)

101 has perfectly good frontage roads from university avenue all the way to san antonio, but doesn't use them as service roads, as I would assume they would be used.

It really seems like the freeways in this area were designed in an era when people thought "Free-flowing is awesome! No more traffic lights! loop ramps for everyone!", before they realized that when traffic gets congested, most people would rather deal with traffic lights than people who don't know how to merge.

Where I come from (long island) that whole strip of 101 would just have service roads alongside it that hit all of those roads at regular intersections.

# ¿ Jul 23, 2013 09:31

Socket Ryanist: Aug 30, 2004

Cichlidae posted:

I would not put signals on freeways. You open yourself up to the risk of high speed rear-end collisions, and frequent ones, at that. Ramp metering is decent, but it can only do so much. It'll also tend to push traffic onto local roads, which will get a lot of pushback from those communities. If you're not going to do geometric improvements to reduce bottlenecks (removing those closely spaced ramps and putting in frontage roads, for example), you will need to do demand management.

There are a few ways to do that. Reducing overall demand is one, asking people to cut back on trips. When gas prices go up, this happens by itself. Unfortunately, that mostly cuts down on off-peak travel, as people aren't going to stop commuting to work. Another way is to get people over to higher occupancy, whether it's carpools or buses. This is a bit trickier, but it can be done. A third way is spreading out those peaks by encouraging businesses to adopt more flexible starting and ending times. Number four is shifting people over to other modes, and that's the hardest way, because Americans are loth to leave their cars behind. It also requires people to move en masse, or a tremendous amount of money to be spent for new infrastructure (light rail, for example.)

The trouble with this area is that everything is so scattered that there really is no feasible alternative to driving for 90% of people, and the roads are laid out so that almost every trip you will take (shopping, commuting, visiting friends) involves a freeway.

# ¿ Jul 30, 2013 08:47

Socket Ryanist: Aug 30, 2004

Cichlidae posted:

I would not put signals on freeways. You open yourself up to the risk of high speed rear-end collisions, and frequent ones, at that. Ramp metering is decent, but it can only do so much. It'll also tend to push traffic onto local roads, which will get a lot of pushback from those communities.

To be clear, I'm talking about freeway-freeway interchanges which consistently bog down to sub-15 mph during rush hour because of merging. For example northbound CA 85 and northbound US 101, or US 101 and CA 92. It also seems like minor accidents occur at these interchanges on a daily basis due to people fighting over merge position, which of course makes the situation even worse. I was thinking it might make sense to just signalize these interchanges during rush hour only and have them be free-flowing at other times.

# ¿ Jul 30, 2013 12:03

Socket Ryanist: Aug 30, 2004

I don't disbelieve you, but I have trouble understanding why that is. Do the models take frequency of collisions into account?

Also, I don't know if this is recommended practice, but California does often use ramp meters on freeway-freeway merges--just only on some of the movements.

Socket Ryanist fucked around with this message at 16:57 on Jul 30, 2013

# ¿ Jul 30, 2013 16:55

Socket Ryanist: Aug 30, 2004

it looks like los angeles to me? :confused:

what's so terrible about it?

fake edit: holy poo poo I can't believe I wild guessed that

Socket Ryanist fucked around with this message at 02:45 on Jul 31, 2013

# ¿ Jul 31, 2013 02:42

Socket Ryanist: Aug 30, 2004

California solved the "many parallel toll booths merging into few lanes" problem by a kind of modified ramp meter where the lanes each get a green in sequence. The lights are only active when traffic reaches a certain level.

(This is actually what my suggestion from earlier was inspired by)

# ¿ Aug 12, 2013 13:04

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# ¿ Apr 28, 2024 00:53

Socket Ryanist: Aug 30, 2004

AmbassadorTaxicab posted:

How are roads in mountainous and very hilly area designed? Is there a certain performance envelope that cars must meet?

It's always a tradeoff between "how big of a truck do we want this road to be usable for" (passenger cars are no problem) and "how much are we willing to put into reshaping the mountain to reach that goal"

# ¿ Aug 13, 2013 04:28

The Something Awful Forums > Discussion > Ask/Tell > Ask me about being a Traffic Engineer!

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