Good morning, I write from Italy and here, where I live, but it is not only here the problem, are launched public roads projects that are breathtakingly bad and obsolete. I am no expert, I just think to have a minimum of good sense to understand that projects that are raping the countryside to build streets and welcome the circulations of more cars, more pollution and that conceive human beings like automatons that are staring the tv, then the windshield and then again the monitor at work. Imagining human life this way, in 2023, is a bit of a nightmare. Thus I would like to educate myself on traffic egineering. Is there someone out there that can point me YT channels; podcasts or worth to read books about this subject? At least, when there will be a public meeting, a city hall pubblic assembly I can think of intervening and say that there’s something better that just open roads after roads, after roads. Thank you
Not always the case, but you’re not wrong. Most of the times the new road or added lanes was needed because the traffic density had already increased. Kind of a chicken or the egg scenario. For a new road, well roads arent just built for no reason…obviously the road was needed, so now there will be traffic on it. Sometimes even just an influx of people using the new “alternative route” because they think no one will be on it from the old route, yet many other people had the same idea.
Exception to all this, however is evacuation routes. I grew up in the south, on the gulf of mexico. When hurricanes are coming and everyone is trying to leave, you need those huge highways. 30 years ago you would just have 1000s of people grid-locking 2 lane highways just trying to get anywhere away from the storm, and in some cases being stuck in their car for the storm. Now a lot of those highways are full-on 4 lanes with medians, huge shoulders, etc. These are everywhere across the south, more still being built. Even extra bridges built across bays and sounds that are largely unused (usually have high tolls). 99% of the time the big highways are mostly empty (which makes road trips super nice!) and someone not familiar would think it’s a huge waste. But come an emergency situation, and their purpose is served!
An excellent point I hadn’t considered!
It’s definitely the egg, since the chicken was the road and the egg(traffic density) increases after adding another highway or lane to a “super highway”.
Before that highway or lane was added, there was less congestion.
Ehhh, i still disagree, because that doesnt make sense. Less congestion with less lanes? The extra lanes are added to ease the growing congestion in an area. OP asked about traffic engineering, there is it very simply. Adding lanes doesnt magically create more cars on the road.
I’ve seen the exact opposite in places like Hawaii when they expanded H1 at Honolulu, shrinking all the lanes down to the minimum 8ft so they could add another lane. Now at, I think 6 lanes each way, in places. No space to expand, so the lanes were shrunk to make room for another. You know what adding another lane did? Lessen congestion. Sure there’s still congestion, but it’s way better. They, and other big cities (ie- San Fransisco), literally add and change lanes throughout the day (zipper lanes) to ease congestion. Or even legally allow the shoulder to become yet another lane during peak hours. Because more lanes = more flow.
I’ve also seen what happens when the extra lanes arent open (like the zipper lane cant function because the truck is broke) the whole place is gridlocked taking people up to 9 hours to get home. Because of 2 less lanes.
Not just in America. Places like Auckland, NZ and their famos Nippon clip-ons. If adding lanes added congestion just because of the fact that there is more lanes, then why are roads expanded in the first place? Everything should just still be 2 lane roads.
Adding more lanes does not “magically create more cars on the road”, but it does mundanely create more traffic, so that increasing traffic lanes provides diminishing returns of reduced congestion.
You have to factor in how many cars are acquired every year, how many people are driving, how they are driving where, and when.
Every year people are buying new cars and the old cars don’t just disappear, more people move to where more people already live, and adding new lanes only invites more drivers to where everybody is already going.
A simple, related and more accessible example is adding parking spaces into a downtown area. This does not lessen congestion but increases congestion as more people drive downtown and everyone drives around looking for a parking space rather than walking an extra 7 minutes from a less congested area.
A similar thing happens with highways, and research backs it up.
https://www.bloomberg.com/news/features/2021-09-28/why-widening-highways-doesn-t-bring-traffic-relief
https://smv.org/learn/blog/how-does-roadway-expansion-cause-more-traffic/
Improve mass transit and public transportation and this problem evaporates.