Plan B Forum

That does seem a bit ridiculous; I always thought the point of roundabouts/circles was to avoid the use of traffic lights/signs.

On some major intersections, even a roundabout can get completely jammed by sheer volume and human cussedness. You'd be grateful for traffic entry control when there are multiple lanes - 3 and upward - with folks trying to change lane to get to their exit. It's also the great equalizer . . . it's often the case that one can't get onto the roundabout on a particular entry road because there's never a break in traffic already going round. That's when accidents happen as the frustrated waiting driver finally gets tired of the hoots from the folks waiting behind and takes a chance on penetrating the wall of plastic and aluminum whizzing round.

Also, when you get on a big roundabout and you choose the wrong lane (or can't get over to it) the lights are a boon as they give you a platform to stop, wait and then zoom away on a diagonal to achieve the goal

For an alternative view (and it's worth the read)
https://waterfordwhispersnews.com/2015/ ... perfectly/

I can see that Meade, but when the traffic signal is installed, why keep the roundabout? Just use the signal to control the access to each lane.

Looking at the photo in you attached article, people generally have the need to proceed straight, left, or right, and a properly timed signal could expedite all of this more efficiently than a roundabout.. True, people cannot reverse direction on the same road that way (effectively make a U Turn), but there are other ways to handle that (and I doubt that it's that much of a concern in most cases). I d on't see a reason to keep the roundabout after the signal comes.

From what I have seen, roundabouts are best in places where the traffic doesn't support installation of a signal, and is superior in many cases to just installing a stop sign at the installation (especially where there is some traffic at times).

We have many roundabouts here in eastern Massachusetts, no doubt because we were mostly Brits first. Roundabouts don't work well when so many people using them are stupid.

Kind of like the reason why 4 way stops don't work in NYC.

Big RR wrote: ↑

Tue Mar 26, 2024 1:28 pm

I can see that Meade, but when the traffic signal is installed, why keep the roundabout?

Because it's there, duh! No need to dig the entire thing up and relay roads at a cost of millions. These are often 5 to 6 entry roads

I wouldn't think that the costs would be that high, but I guess cost savings would be a reason. However, I think lights and roundabouts only cause more problems/inconveniences for motorists and if lights are installed, the roundabouts should be removed eventually.

I can see the use of traffic signals to get on the roundabout but once on it makes no sense to stop.

How about that Francis Scott Key bridge?

🥹

I just heard about it; Baltimore will feel the effects for a long time. I heard it was a tanker that hit the bridge, but haven't heard anything about an oil spill.

Big RR wrote: ↑

Tue Mar 26, 2024 6:49 pm

I just heard about it; Baltimore will feel the effects for a long time. I heard it was a tanker that hit the bridge, but haven't heard anything about an oil spill.

This is going to disrupt the port, which I read is one of the busiest ports on the east coast for specialized cargo like trucks, tractors, and trailers, as well as a stop for several cruise ships such as Royal Caribbean's Vision of the Sea, the Carnival Line's Legend, and American Cruise Lines' American Glory.   Now, nothing is going to be getting in or out until they get the channel cleared of wreckage.

Big RR, the ship that struck the bridge pier was an outbound container ship — and where you have outbound container ships, you also have INBOUND container ships, which are no longer going to be able to get in to offload their containers of imported crap from wherever.   So be prepared to see the prices for everything from tractors to toothbrushes go up in response to this catastrophe, just like gas and oil prices go up every time something happens to slow or stop production at a Gulf Coast refinery.

-"BB"-

The ramparts were so gallantly lacking....

Crackpot wrote: ↑

Tue Mar 26, 2024 5:06 pm

I can see the use of traffic signals to get on the roundabout but once on it makes no sense to stop.

Well if you don't stop somewhere no one else can get on. I think you guys are imagining dinky little 1-lane each way 4-road intersections. Try three lanes with five or six roads coming in and a roundabout that's about a 1/4 mile across with a nice forest in the middle.

One solution I've seen on the old Arterial between Basildon and London for a small roundabout is to just block off the roundabout on two sides . . . then it's just a four-way intersection with a really weird centerpiece

There is a lot of online chatter about how the Key bridge collapsed and I am left with the undeniable truth that bridge physics is not well understood by the masses.

I have driven that bridge, usually when I was coming or going to BWI airport. It looks big. But that 'boat' with pieces of the bridge wrapped around makes the bridge look tiny. Latest news item I have seen says the container ship issued a 'mayday' call before the crash. That reminds me how old I am. Once upon a time 'mayday' was for airplanes and 'sos' was for ships. SOS was a relic of morse code -- a simple rhythm easy to send and easy to recognize. Mayday was a bad vocal French cry for help. Early this morning CNN was showing video of the actual event, and it was clear the running lights on the ship went dark before contact with the bridge.

snailgate.

BB--thanks for the update.

BSG--I have no doubt about that; science illiteracy is pretty common.

This morning on the radio I heard competing engineers. On the Philly NPR staton I heard an interview with an engineer from the local port authority. He said the bridges in Philly did not have a similar hazard because the river bottom was carefully shaped with rocks and other barriers to cause the ship to go aground before it got near the bridge supports. Then the Nat'L news from NPR interviewed an engineer from Johns Hopkins U, (a Baltimore institution) who said bridge supports there just could not be similarly protected. He did not say it but my mind said Baltimore is a deepwater port and Philly is not. My own view is that before the era of computer analysis civil engineers said to themselves 'What will it take to withstand a worst case scenario? OK, now let's double it.' Now 'we know better' and can calculate the potential stress and not waste any un-needed material 'just in case'.

Aint no 21st century construction gonna last like the pyramids any more. i can't even get somebody to design a home that will last 50 years without major maintenance, even though there are at least a couple in this town that have lasted twice that now. One is early re-inforced concrete that is now a luxury office in the midst of an industrial park, because the developer said it would be way too expensive to tear it down.

For all of you out in the mid-West that think global climate change is not gonna hit you -- you only need to take in the growing possibility of extreme wind and water (and lack there of) What'll it take to re-create the sea that produced all those current salt mines in Kansas?

snailgate

When I worked as a safety consultant in the chemical industry (back in the days when slide rules were almost as common as calculators), the joke was that engineers calculate everything to the fourth or fifth decimal place (they usually had he calculators) and then double or triple it for a safety factor. While I am pretty sure this degree of overkill might not continue, I think they do factor some of it in the safety calculations (just not as much). That being said, I do think they plan on much shorter lifetimes for structures, and save money, in a lot of other ways.

I recall a friend of mine who bought a big, expensive, house with 4 forced air furnaces (a cheaper alternative to hot water baseboard, even though multiple furnaces are required to give different "zones"); two of the furnaces were lay down furnaces in the attic, and they were place adjacent to the access so you had to climb over them to access the attic. It would have been fairly inexpensive to relocate them during the building of the house, but instead it cost my friend thousands to get it done (contractors just don't like working in the attic) and, while a single HWBB installation might have cost a bit more (especially if you factor in the cost of installing air conditioning vents in addition to the baseboards) there would be only one furnace to maintain rather than 4. I do think that way of thinking pretty common.

The ground was lower then. I live in an area surrounded by 1/5 of the world’s fresh water that also sits atop large quantities of salt. You melt all of the earths ice and the water levels will not likely hit the upper 4 Great Lakes.

Crackpot wrote: ↑

Mon Mar 25, 2024 11:38 pm

Who the fuck puts traffic lights on roundabouts?!

That's just dumb. But there are a surprising number of people who have never encountered a roundabout (or "circle" as we call them here), so I guess they need all the help they can get.

Crackpot wrote: ↑

Mon Mar 25, 2024 11:38 pm

Parking sucks and I’m glad I don’t plan on moving my car til I leave.

DC is small enough that you can get pretty much anywhere you need to go by walking and/or Metro.