Background

Tokyo Metropolitan Expressway, which had been developed since 1960s, connects not only to the surrounding areas but also to Tomei Expressway (bound for Osaka), Tohoku Expressway and other major national expressways to form a wider road network.
The following challenges were identified before the revision.
・Toll rates and vehicle categories were varied according to the route and section
・Toll rate via Metropolitan Expressway was lower than that via the Metropolitan Intercity Expressway to drive through the center of Tokyo.
・Higher toll rate and a terminal charge that was imposed for every routes of different operators.
With these challenges, a more reasonable concept for toll rate setting "Three smart principles of expressway toll rates in the Greater Tokyo Area" was created. All expressways in the area surrounded by the Metropolitan Intercity Expressway were subject to the concept.
1. Fair toll rate depending on usage: A distance-based, fair toll rate system on the beneficiary-pays principle.
2. Seamless toll rates regardless of difference in operators: Integrated toll rate system among expressway operators.
3. Strategic toll rate to optimize traffic flow: Toll rate system to induce traffic from congested routes in the urban area to less-congested routes.

Details of the revise

Outline of new toll rate system which was introduced on April 1 2016.
1. The toll rates for Metropolitan Intercity Expressway are lowered (same toll for the same origin/destination)
2. ETC2.0 equipped vehicles are subject to further discount
3. Tolls for Tokyo Outer Ring Road will be discounted if a driver uses it to the central Tokyo
4. Drivers going through the central Tokyo will be charged depending on the traveled distance

Effects of the toll revision

The following effects have been experienced 1. Through-traffic was shifted to outer ring roads, reducing congestion on Tokyo Metropolitan Expressway
-10% reduction of through-traffic in the central Tokyo, with 50% through-traffic reduction between Tomei and Tohoku Expressways
-1% reduction of traffic on Tokyo Metropolitan Expressway
2. Smoother traffic on general roads due to increase of short-distance use of Tokyo Metropolitan Expressway
-Short-distance users of the Tokyo Metropolitan Expressway increased by 1 to 4% due to the lowered toll and reduced congestion with less through-traffic.
-Traffic volume on the Tokyo Metropolitan Expressway (Shibuya Line) increased by 2% while the parallel national highway No. 246 decreased by 7% around Minato-ku Aoyama.
3. Network development and toll discount promote use of Metropolitan Intercity Expressway
-Traffic on Metropolitan Intercity Expressway increased by 30% (additional 5~8% increase after it was connected to Tohoku Expressway)
-A significant increase of distribution centers that are newly constructed in the areas along Metropolitan Intercity Expressway by 4.6 times (or by 2.7 times in the Greater Tokyo Area)

More details of toll rates are provided at the site below (Japanese text only)

Official site about new toll rates for expressways in the Greater Tokyo Area