Tokyo Expressway(D8) is short for a toll-free road of the Tokyo Kōsoku Dōro K.K., separate from the Metropolitan Expressway. Getting on a Tokyo Expressway(D8) from the Metropolitan Expressway requires first getting off the Metropolitan Expressway, but every terminus of the Tokyo Expressway(D8) is connected to the Metropolitan Expressway. Thus, no base toll is collected when reconnecting to the Metropolitan Expressway from a Tokyo Expressway(D8) without getting off onto a local road.
Using a Tokyo Expressway(D8)
There are two ways to use a Tokyo Expressway(D8).
1. Pass through a Tokyo Expressway(D8) coming from the Metropolitan Expressway, then use the Metropolitan Expressway again
2. Get off the Metropolitan Expressway onto a local road at a Tokyo Expressway(D8) exit
Here is a description of the rules for "connection" in (1).
Drivers who passed through using the same ETC card remotely can pass through (1) to (4) below without taking further steps. However, drivers should connect from (2) to (3) within 10 minutes. Another toll will be collected if 10 minutes is exceeded.