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Michigan Lefts are a way to reduce accident severity at intersections. They do this by removing left turns at high speed intersections. Accidents from left turn movements can be one of the most severe of any types of accidents so wherever you can, you want to avoid them. I think they are a great idea and as long as you have the real estate, they should be put in place.quote:As a OTR driver, and since that's RIGHT next to the Flying J, I can truly say that one sucks. They never make the road wide enough to account for trailer offtracking, and if you are all the way out to the DOT with your tandems, the poo poo in the middle of that roundabout is gonna have a visit from Mr. Trailer Tires. That's what the apron around the center circle is typically designed to do. Drive over them to your heart's content. Neutrino fucked around with this message at 20:46 on Jul 31, 2009 |
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Jul 31, 2009 20:44
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Cichlidae posted:This guy knows what he's talking about Please, Traffic Engineer? No, I'm a Highway Design Engineer. Tut.
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Aug 1, 2009 03:09
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Are you a traffic engineer, too, or just a roadgeek?
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sc0ticus posted:I would love a discussion on Traffic Jams. What causes them? How do you model them? Do they have predictable flow and what do traffic engineers due to prevent them? When the road/highway gets near capacity which happens during peak hours, it doesn't take much to cause a jam. Lane changing, merging, talking on your cell phone, changing radio stations, etc can cause slow downs which cause a ripple effect. Hitting brakes is a psychological distraction to other drivers which probably does the worst damage to interrupt flow. Leaving enough room between cars can alleviate problems by allowing merging or lane changing vehicles to do their thing without sudden braking. Driving in the wrong lane? When you get near capacity there is no wrong lane. Most traffic will be running near the same speed and more densely packed than is desired. On a four lane highway that is operating normally, a person driving slowly in the "fast lane" will prevent speedier drivers from driving what they think they have the right to drive. That does not cause traffic jams unless you get those speedier drivers tailgating and driving recklessly. More often than not you get somebody tailgating or trying to cut off the wrong person. Nobody can drive faster than the flow of traffic, so it doesn't solve anything to get pissed at the guy in front of you for driving slow when he is stuck behind slower drivers like yourself. The best thing to do is to relax and leave space and avoid braking (unless you absolutely need to)!
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Aug 1, 2009 16:37
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Cichlidae posted:Seeing as the R R Y G is available in both horizontal and vertical configurations, why doesn't Texas go tall like the rest of us? Maybe because horizontal indications are cheaper, since they require shorter mast arms or span poles. It looks like they save money on near and far lights and just use triple fars on a mast arm. Here is a typical Street View. It makes sense based on that configuration. The double reds apparently are used for left turns so drivers don't get confused when the through red lights change. I would be confused without near signals but that's because I live where we typically have snow covering stop lines in the street for several months. It also would be a bitch because if the pole gets taken out in an accident there is no redundancy leading to more accidents until you get a signal maintenance crew out there to fix things. Neutrino fucked around with this message at 17:03 on Aug 5, 2009 |
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Aug 5, 2009 17:00
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ilkhan posted:I80 between auburn and reno (the sierra nevada stretch) is basically repaved every 2-3 years because of the snow and the volume of truck traveling it. The road is consistently horrible. Heavily loaded trucks are not good for roads. IMHO, a lot of transport should be done by rail and weight limits should not only drop but be more strictly enforced. Rail can handle tonnage much better and cheaper than even the most heavy duty road designs. Trucks, more often than not will destroy roads without contributing much to their upkeep costs. Day after day I see the damage that large semi-tractor trailers do to pavements, walks, and curb and gutters. Minor settling on concrete pavement panels will receive a jack-hammer effect from heavily loaded truck tires traveling at freeway speeds shattering pavement within months. Cichlidae posted:There are some pretty neat innovations that have come up in the last decade to fight snow. Embedded pavement sensors can detect when the pavement temperature drops below freezing, and notify the plows to come get rid of the snow/ice. Additionally, some states have been experimenting with nozzles that automatically spray anti-freeze solution onto the pavement once it hits freezing. Generally those are used on bridges and only in problem areas due to the obvious high costs. A good DPW will know their roads and weather so it isn't hard to keep on top of plowing and ice control. Western states in the mountains may have to deal with more variable conditions over a greater area which may require that type of system along some stretches but again, only in problem areas.
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Aug 7, 2009 04:24
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Simkin posted:
Yeah. I talk to the guy in our office in the traffic section and he changes the sensitivity on the loops. It helps to center the bike over the corner of the loop where the line runs to the curb. Usually it is visible which makes it easier. If you have to wait more than two cycles, the loops aren't picking you up, so you have a legal right to go through the red. Cops will be understanding because surprisingly many own bikes.
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Aug 7, 2009 21:58
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Cichlidae posted:Where does it go from here? Some people think we'll switch over to electric cars, maybe biodiesel, and the price of oil won't be an issue. That means we get to keep our suburbs, our long commutes, our American way of life. I, however, don't want this to happen. Among American traffic engineers, I'm probably in the minority, but I want us to consolidate and use more efficient forms of transportation. Yes, it sucks to trade in your big backyard for an apartment in the city. Yes, the bus is inconvenient, and the guy sitting next to you smells like manure. We'd all have to make major sacrifices in the name of social efficiency. I feel the same way and there are growing numbers of us. I've lived abroad in a major city where having a car was a liability. It is painfully easy to live without a car 99% of the time there. A decent sized grocery store is only a few blocks away. Subway stops are easily accessible. Buses are even more accessible. Even taxis are usually reasonably priced if you've got bigger things to transport. I bought a computer desk from someone on the other side of the city and just disassembled and brought it back home in a taxi for about $10. There will always be enough work for engineers even if traffic was halved tomorrow.
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Aug 10, 2009 22:11
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Portable591 posted:Back to bikes: Are there any guidelines in the Green Book or any of the standard texts regarding bicycles? AASHTO has a Guide to the Development of Bicycle Facilities from 1999. It is the "Green Book" for bicycle facility design.
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Aug 13, 2009 15:50
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Cichlidae posted:
You'll notice it isn't from the AASHTO website...
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Aug 13, 2009 19:27
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People should learn not to solely rely on the traffic signals to let them know when to go. There are plenty of drivers that will try to "make the light" even when it has already turned red. I learned from riding a motorcycle never to go until I made sure all the cars on the cross street were stopping or stopped.
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Aug 13, 2009 22:10
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Cichlidae posted:
I'd recommend the book. I got it for a Christmas present last year and it gives a pretty good analysis of traffic engineering, although it was written by a journalist. Vanderbilt does a good job of research and does provide lots of information and studies that shed light on the driver side of things. Its illuminating even for an engineer.
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Aug 17, 2009 15:15
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quazi posted:For whatever reason, somebody probably thinks washboarding, potholes, and undercarriage scratches caused by patch jobs on top of patch jobs gives the place character! Instead of actually fixing the road, we seem to pride ourselves in how many squiggly-rear end lines we can paint all over the place: Actually the tarred cracks are a sign that the county highway departments do care about maintenance. Some places don't tar cracks which leads to roads disintegrating in the winter.
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Aug 18, 2009 16:11
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Kelson posted:I guess that's the question I'm trying to ask; how do we minimize cost without (significantly) impacting ride quality or safety. For example, if concrete and asphalt are both acceptable, then what are their respective life cycle costs? Asphalt costs are more directly tied to the price of oil and as such their per unit costs can change dramatically. Granted the asphalt price does not fluctuate as quickly as gas prices and once a contractor makes an early bid for summer construction they are bound by their prices. Right now, the oil price is projected to increase so I'm guessing that asphalt bids will be a little higher than usual for the coming construction season. Still, concrete is generally 5-8% higher in cost although if oil costs climb again, that could change. Generally we look at a 30 year LCCA for asphalt vs concrete. Wisconsin uses a program they developed called WISPAVE which has a built-in asphalt bias. It analyzes the complete life cycle cost for both materials with more maintenance for asphalt. It sucks but is a requirement for jobs financed by state funds, even local roads.
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Mar 24, 2010 15:25
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Cichlidae posted:Yes, they're quite variable, and the answer to which is better in the long run really depends on who you ask. I went to an ACPA seminar, and of course the lecturer went on and on about how concrete was much more economical than asphalt. A lecturer from Shell, on the other hand, had nothing but praise for asphalt. Almost anyone you talk to is going to be biased one way or another, which is why Rhode Island and Connecticut generally pick a policy and stick with it, rather than analyzing things on a case-by-case basis. Costs do vary by region based on the availability of materials. Wisconsin and the Great Lakes region has a good, cheap supply of cement as well as stone. At a recent nuclear density training class I was talking to an engineer from Hawaii. He mentioned that aggregate costs are well over double what we have here. Obviously they have to ship it on barges from the mainland US.
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Mar 25, 2010 13:58
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IOwnCalculus posted:That sounds almost like the passing lane solution everyone else is discussing...but at the same time it sounds like the suicide lanes a very small number of the roads here in AZ have. I think the one in Tucson was shut down and turned into a regular turning lane, but at least a couple of streets in downtown Phoenix still have it set up so that during morning rush hour, the center lane is part of one side of the road (no left turns) and during evening rush hour, it goes the opposite direction, and outside of those hours it's a left-turn lane. I like simple systems that can adapt to varying traffic volumes like this. It makes roadways more efficient and saves on construction costs. For regular commuters familiar with the operation it can work well but for tourists, drivers unfamiliar with the area, and old people this is an accident waiting to happen. Milwaukee is about midway on a multi-year program to convert all its downtown streets to 2-way. Most regular commuters love one-way streets for their efficiency and easy ability to handle peak-hour volumes. But I regularly see people that can't read the multiple signs that say, "ONE-WAY" or see that all the cars are parked in one direction or see cars heading toward them in all lanes. Safety trumps efficiency.
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May 21, 2010 14:09
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Kakairo posted:I was browsing randomly through Wikipedia, when I came across something for this thread: A lot of non-uniform devices are used until there is a lawsuit.
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Jun 11, 2010 18:40
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Wisconsin just passed legislation to allow u-turns at all unmarked intersections which left cities all over the state scrambling to post no u-turn signs.
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Jun 21, 2010 18:44
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Dr. Leo Spaceman posted:What does it mean when a regular street light is flashing red, and why does this happen? Street light or street signal? A street light flashing red could be a sign of the apocalypse or it could be a sodium vapor light that is failing. A BS in civil engineering, BSCE, is math and science heavy so make sure you can handle calculus or at least get tutoring. In the real world very few engineers use advanced math but it shows you have some level of competency at handling difficult problems.
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Jan 6, 2011 15:07
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nm posted:I think that's a least coast thing. Never seen it in Minnesota or California except during construction for temporary lights. It varies. I've seen it in the suburban Detroit area used quite often. I always disliked it for the same reasons.
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Jan 7, 2011 15:11
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Entropist posted:But it's less ideal if you want to cross one of the legs on foot when cars don't have to yield to you. You can't see cars coming from the other side, and as a pedestrian you'll have to walk drat fast if a car does appear from behind the scenery right after you checked if it's safe to cross. Cars always have to yield to a pedestrian and at the average speeds in a roundabout they will have enough time to stop when they see you.
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Jan 14, 2011 17:39
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less than three posted:Pretty awesome that it split right down the lines like that. It probably has to do with the fact that the road was built in halfs to keep the road open during construction.
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Mar 11, 2011 23:44
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will_colorado posted:If the US would not have gone through with the Federal Highway Act in the 50's and kept and maintained it's passenger rail and inner city train/public transit. How different would our suburbs, highways, and cities look now? In Milwaukee urban sprawl and the exodus from the city center was starting to rear it's ugly head well before freeways were starting to become a reality. Cars were making a massive impact as a means of transportation starting in the 20s when the cheap Model T was available. Parking and traffic jams were huge problems up until WW2 slowed car production and gas supplies were hard to come by. Public transit had its highest riderships during the war. The city of Milwaukee still had enough transportation engineering clout to fund quite a few projects of its own to link newly annexed lands with efficient, modern roadways some of which were limited access. The suburbs on the other hand, could never afford modern roadways without a sufficient tax base and couldn't grow a sufficient tax base without a modern transportation system. The state has always funded its own highway system that linked cities and towns. It would be likely that they would have increased those roadways into something similar to the modern interstate system if the need grew. Suburbs would still exist but would not be the urban siphon that they grew to be without interstate highways. I don't think interstate trucking and vehicular travel would be as big without interstate highways. National rail networks would be more heavily used than now at least until air travel took over.
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Mar 13, 2011 03:03
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Pffft, that stuff happens here in Milwaukee all of the time.
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Mar 17, 2011 14:05
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grnberet2b posted:I'm kind of curious if requesting a traffic survey would be proper in this scenario. With the looks of the number of openings and driveways on the new stretch 30mph would probably be about right. Also considering that the stretch of road is pretty short it isn't like going faster is going to save you more than 5 seconds from one end to the other.
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Mar 24, 2011 14:32
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Baronjutter posted:What can you tell me about the different types of actual paving different regions use? When is concrete used, when is blacktop used? I notice when I go down to the states all the roads seem harder and bumpier and grayer than where I live, where they're generally much darker and smoother and don't have expansion joints like a sidewalk. For the most part it is an economic decision. On most larger projects we do a life cycle cost analysis to compare both pavements. The cheaper type gets chosen. Some regions may have cheaper asphalt costs versus concrete so asphalt will be used. Either can be used to build a road with the same loading capabilities.
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Mar 24, 2011 16:45
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FISHMANPET posted:I saw a billboard yesterday that was put up by some Concrete industry group that basically said potholes are Asphalt's fault. This is in Minnesota, where freeze-thaw is brutal. The worst potholes I've ever seen in my life were in Minneapolis on the interstate. Milwaukee has some good ones but the highway is patched well. The deepest, nastiest are typically on concrete roads that are poorly maintained. Tarring joints has to be a regular program and have to be done well. Too many tarred joints are pulled up by plows in the winter and by spring are ready for ice damage.
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Apr 4, 2011 19:52
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smackfu posted:I didn't realize there were still wooden bridges in CT. This is in Middletown on West St. There's no code that says this kind of thing has to be replaced by now? (The approaches are steep enough and the bridge is narrow enough that it needs Stop signs on both ends to make sure people don't blindly fly through it and collide head-on.) Wood bridges can be much longer lasting and cheaper than concrete or steel. Wisconsin has actually built quite a few timber bridges in the northern part of the state in the last several decades which are used in areas with lots of logging operations. One of the most impressive highway bridges I've seen is the Keystone Wye Bridge built in 1968 on US16 in South Dakota. It used glulam arches on the upper span which crosses the lower glulam span. In college I took a wood design and engineering class which taught us many impressive properties of timber and glulam.
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Apr 18, 2011 17:27
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nm posted:^^^^^^^^^^^^^ The painted traffic markings spell it out. They signify that there is a rail crossing and that vehicles in the road must give the ROW to the train. Also if you look closely there are crossing gates. Any sign designating a crossing means that you must yield at that crossing whether it is pedestrian, deer, or railroad. Deer aren't going to sue you but they will leave an impression on your car. Neutrino fucked around with this message at 18:24 on Apr 20, 2011 |
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Apr 20, 2011 18:20
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drunkill posted:
It's hard for me to make sense of the "backwards roads" in the Queen's realm. I'm just used to the standards of roadways in the rest of the world.
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Apr 28, 2011 19:02
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Heh, our union had to take a 0% wage increase and other concessions two years ago to avoid layoffs. Now our newly elected governor is hellbent on abolishing all public sector unions except for police, of course. Not to mention he is trying to enact every bill he can to destroy our city by cutting funding and making other rules that force us into obedience.
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May 25, 2011 17:58
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The NCHRP 350 uses a larger test vehicle than the European code so our guardrails will be more substantial than those required in Europe. The test vehicle in the US is a 3/4 ton pickup truck which is 2000kg whereas it looks like yours is 1500kg.
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May 26, 2011 14:28
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Drunk Tomato posted:I want to write a short letter to my city's public works department (which encompasses traffic and streets matters) regarding the signal length of a particular left-hand turn lane. This light is green for only enough time to allow 4-5 cars to pass, when in the morning there can be 3 or 4 times that amount waiting in the designated turning lane. This means that sometimes I wait 2 or 3 light cycles before I can turn. The designated turn lane is long enough to hold about 20 cars, so this means that the city has designed for lots of traffic. For some reason, though, they kept the light ridiculously short. This means a lot of cars end up running the red light here. You are probably better off telling them that there is a problem rather than offering solutions. You should definitely let them know where you are coming from and mentioning the direction you and the other traffic is going. I assume the majority of traffic is coming from the new? apartment complex NE of Slater and 120th. It looks like Slater needs to be expanded from 2 to 4 lanes.
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May 26, 2011 17:58
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In downtown Chicago people leave intersections clear and really make an effort to avoid gridlock. It probably has more to do with this problem being strictly enforced by the police than actual goodwill because drivers down there will look for every opportunity to gently caress other drivers over in other circumstances.
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Jun 3, 2011 14:19
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Drunk Tomato posted:Supposedly, a friend of a friend (yeah, I know) got a ticket because he was "stopped too close to the car in front in front of him". The scenario was this: It doesn't sound like BS. There isn't a law about parking too close but an accident in this situation puts liability on the following cars. A low speed accident will not necessarily cause a chain-reaction accident if the cars are at a reasonable distance. That is the reason why you should leave enough of a gap between you and the car in front. More so if you are stopped on an incline and the car in front is a manual transmission.
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Jun 3, 2011 17:45
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Too much signage and flashing warning lights detracts drivers from paying attention to what they should be paying attention to. Driver's attention will be drawn to warning signs and fail to pay attention to the pedestrian. Flashing lights have some weird hypnotic effect on drivers where it draws every bit of their attention. On highways especially, a cop car with flashing lights on the side of the road will invariably cause other accidents when drivers glance at the police car without paying attention to the slowing traffic in front of them.
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Jun 15, 2011 17:30
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It's hard to tell where the major flows of traffic happen but Buckingham Street could be widened by eating up some of that parking lot to the north. That could alleviate some of the traffic on Capitol Avenue and allow for some good flow around that big stone building. I am weirded out by the driveway coming out of the Capitol building right in to the center of the intersection. That could easily be changed which would most likely solve some problems. The entire driveway is a hideous design and using the area around the Capitol as a parking lot is beyond gross. If you need extra parking then bury a parking structure under Bushnell Park and leave the surface area as a park/public assembly area.
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Jun 16, 2011 03:43
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Cichlidae posted:Oh man, you can't touch that parking lot. That building is the Department of Administrative Services, and if you touch their land, they'll make your life a living hell. Heh, heh. The "sea of surface parking lots" behind the Administrative Services building is passe. That went out of fashion in the 1970s. You think they'd want to hide this embarrassment of civic design and show their commitment to the 21st century by doing something green. Or is CT, the place where everyone still drives vintage caddies and smokes big cigars?
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Jun 16, 2011 14:19
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Around here they flash all-red on a power outage. Although I have approached an intersection once with the lights completely out. Now that was scary as gently caress because the average tard will see an unlit traffic signal as meaning "full speed ahead". Getting two tards together under those circumstances is pretty damned easy but I didn't wait around to see that.
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Jun 20, 2011 03:43
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There are plenty of reasons why they build a temporary bridge and it is done often. In Milwaukee they built a temporary bridge early last year prior to Zoo Freeway reconstruction which has yet to commence. The main reason there was to replace a bridge that was severely deteriorating. Final interchange plans still need to be approved so this is an interim solution.
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Jul 5, 2011 18:43
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Bumming Your Scene posted:You could use a different surface instead of painting. It's the color of the aggregate. When an asphalt pavement starts to wear, the color of the aggregate becomes the main color. In most areas, the stone is a white/gray color but some areas of the country have a reddish stone and some use quartzite which can be purple.
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Jul 8, 2011 19:45
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