I still can’t remember what I wanted to say in the previous post…
(This column is not FFXIV-related)
#106: “Creations Derived from Hypothesis, Verification, and Discussion”
Published in 2018/04/12 issue
It’s been a while since I started driving to work. I’m boring when it comes to hobbies and interests, but I do love snowboarding and driving. It’s also rare for me to go home before the last train, so in addition to the mental refresher, it’s like killing two birds with one stone. By the way, the reason I can’t go home before the last train is because of voluntary work and playing FFXIV in the office. It’s not because of exploitation. I just want to make that clear.
So, I quite enjoy my work commute. However, the one low point is the traffic jams on the Shuto Expressway. Every morning when I’m putting up with that awful traffic, I ponder why traffic exists. First of all, there are two types of traffic: sudden traffic jams with a clear cause such as accidents, and traffic that occurs naturally without any sort of accident. The Shuto Expressway does have a lot of accidents, but the latter type is even more common.
Accidents are the cause of sudden traffic, but I hypothesize that the primary cause of accidents on the Shuto Expressway is actually the high frequency of natural traffic. People get frustrated because they have to be somewhere on time, and end up doing unsafe merging and passing. I also think that the merging from local roads onto the Shuto Expressway is a major problem, because the left- and right-side merges aren’t separated.
In Japan’s traffic rules, cars generally drive on the left, and so Japanese cars are built with the driver’s seat on the right side. This way, you have a wider field of vision on the right side, to better avoid contact with cars traveling in the opposite direction towards you. Accordingly, merging from local roads onto an expressway is usually done from the left. Of course, sometimes it’s done from the right (such as when going towards Nagoya), but generally the roads are built for left-side merging, unless local residents’ circumstances require otherwise. This is because it’s safer for all parties if you merge from the direction that provides the best visibility.
However, since the Shuto Expressway was added to over time, there are an excessive number of right-side merges. In the worst cases, there are even right-side merges that come after a curve, which make you think, “I can’t even see the cars behind me that well myself, so how are the people on the main road supposed to?” Everyone drives more cautiously to avoid an accident, and hitting the brakes leads to increased natural traffic.
Also, something that puzzles me every day when I’m on the Shuto Expressway is that there is a certain section that never fails to be jammed up, despite there not being any accidents, entrances or exits, or toll booths. When you’re driving through it, there is definitely traffic. But then, seemingly for no reason at all, the traffic will suddenly clear up.
After driving through it every day, examining the flow of cars, and comparing the situation with and without accidents, I’ve somehow managed to pinpoint the cause of the issue (or so I believe). The section that I was describing above is in the Yamate Tunnel, near Nakano. This section is an extremely gentle slope combined with a wide curve to the right. Here, the walls of the tunnel are lit up with blue lights at fixed, short intervals, which naturally draw your attention to the curve. I surmise that they were probably placed in order to prevent accidents.
Since there’s that extremely gentle slope, your speed will naturally drop even if you don’t press the brakes. So, drivers will be affected by this natural speed drop whether or not they’re conscious of it. Plus, to me, those blue lights seem like caution signs, which makes me feel tenser when I drive. This road connects to the Tomei Expressway (which links Tokyo to Nagoya and is used heavily in logistics) as well as Haneda Airport, meaning that there are a lot of trucks. Trucks are heavier than regular cars, and even more so if they’re packed with cargo. This means that when they sense their speed dropping, it takes much longer for them to regain that speed than it does for regular cars.
Combining these factors, we have the subconscious slowing down that tends to happen because of the curve, the natural slowing down from the slight upward slope, and the time it takes for trucks to recover from these effects, which leads to cars behind them braking more often. We can then hypothesize that the natural traffic is a result of this.
After hypothesis comes verification, so I paid a visit to good ol’ Google. The part of my theory that I felt was too weak and subjective was the blue lights, so I searched for “blue lights Shuto expressway.” While I didn’t find an exact match, I did learn about the existence of “escort lights” (please look them up). However, this didn’t match up with my hypothesis, so next, I searched for “escort lights Yamate tunnel.”
“Whoa!” I exclaimed, as I read through a publicly-released document from one of the Shuto Expressway Company’s regular meetings. It described the anti-traffic measures for the aforementioned road. The blue lights weren’t escort lights (which protect against speed decreases), but it didn’t say they were curve warnings, either. However, the cause of the traffic here was determined to be: “The Nakano-Chojabashi exit and the Nishi-Shinjuku Junction exit are both on the right side, so there are a lot of cars in the right lane in this section.” The document suggested keeping to the left lane to avoid this.
However, as someone who actually takes this route every day, I feel like my experience differs from the document’s conclusion. There are extremely few cars that take the Nakano-Chojabashi exit. There’s a high chance of getting stuck in traffic when you exit onto local roads, so if you’re going there, you’d rather continue until Nishi-Shinjuku Junction and exit onto the Koshu Highway from there. The stretch between Nishi-Shinjuku Junction and Takaido is also prone to extreme traffic, so while many people do go there, I’m sure that just as many avoid it. This is also just conjecture, but it’s based on empirical observation (since I take it every day).
Basically, there aren’t that many cars in the right lane. In fact, people who are exiting at the Nishi-Shinjuku Junction would be in the left lane to avoid people who are exiting at Nakano-Chojabashi (which comes right before it), and only switching to the right lane after passing that exit—because it’s smoother that way. Meanwhile, the blue lights make you more conscious of the tunnel walls, and even feel like they guide drivers towards the right lane. I strongly hope for a reinvestigation of this area.
It’s fun to think about things, form a hypothesis, and verify it. Using that as a basis for discussion and “creating” the right answer is even more fun. I think that game development is exactly the same thing. How about that?
 TL note: Okay, you’re not going to be able to find an English explanation of these (or at least, I couldn’t) so I’ll do it here for you. Escort lights are implemented on the Shuto Expressway for the purpose of alleviating traffic (and it works). The lights are placed along upward slopes, with the intervals set in a way that leads drivers to go more quickly, mitigating the natural speed decrease. You can see some pictures of the lights here: https://www.shutoko.jp/ss/shutokonews/tool/201709.html