Overview

The ML Bypass is a concept I am still working on developing.

Having spent a lot of time in Austin, Texas, I've come to appreciate their highway-design, especially in and around the city. One of the concepts they use that I love is the elevated highway system. Basically, it allows high-speed traffic to continue moving, while providing exits that lead to a lower-priority line. This line provides access to the city streets and businesses. Near downtown, they have an even higher-priority line that bypasses the entire downtown area to allow through traffic to get through without any interference at all.

I'm certain this system could be very useful in a OpenTTD map that contains multiple mainlines. The bypass would connect to two BBHs and would not allow traffic to enter, leave, or even switch tracks (for multi-line) between those two points. Because there is a BBH at each drop site, this would allow trains carrying goods and steel to have access to a high-speed uninterrupted line between their pickups and drops. The line can also be used by trains switching from one mainline to another to access a station on the far end of the new mainline.

(example image of ML bypass)

Using a waypoint (or non-stop station) at the entrance of each ML bypass will direct trains to use the bypass over the normal mainline.

Advantages:

• non-stop uninterrupted service between BBHs and Mainlines
• allows expensive cargo (goods, steel) to arrive at destination much quicker
• normal mainline and SL traffic not affected by "through" trains

Disadvantages:

• requires extra planning to implement (extra lines, waypoints)
• extra space required to build (LL_LLRR_RR or LL_LR_RR)
• bypass receives priority at BBH
• SL junctions slight more complex due to extra lanes to tunnel/bridge
• trains may opt to use the bypass, and then need to u-turn to access the station on the bypassed mainline. Use non-bypass waypoints to avoid this situation.

Additional Notes

At times it may be permissable to allow for normal mainline trains to enter the bypass. This should always be done with priority on the bypass, and only in cases where there are numerous congested SL merges on the line ahead. The bypass must NEVER exit before the BBH, or it runs the risk of becoming congested itself.