## I nducing Traffic Diversion with Toll Discounts

Heavy traffic is becoming a chronic problem due to regular and through traffic on roads going to and from the suburbs to the city center, particularly in metropolitan areas. Normally, there are two routes for getting from one point to another, and if the toll is the same for both routes, most people will choose to take the shorter route. However, this can be one of the causes for the traffic jams. By creating a price difference between using the central circular route and using the inner circular route to make the central circular route a more attractive choice, we can ameliorate the traffic congestion and both routes can be used more efficiently.

In January 2012, the Metropolitan Expressway decided to implement a discount for using the central circular route bypass (2-1-1), in order to divert the traffic flowing into the city center to the central circular route to help alleviate the heavy traffic on the inner circular route. Under this scheme, if a driver used the central circular route to go around the city center, a standard vehicle would get a discount of JPY100, and large vehicles would get a discount of JPY200 (JPY210 discount since April 2014). The scheme – which was limited to ETC vehicles – would apply the discount to a vehicle as it went through the entrance and exit to the central circular route, the discount was applied when using the central circular route was a longer route than using the inner circular route.

As a result of implementing this scheme, the amount of traffic on the inner circular route has decreased, and the amount of traffic diverted to the central circular route has increased (Figure 2-1-2).

## Elimination of Flat-Rate Zones

In 2012, the Metropolitan Expressway and the Hanshin Expressway transitioned from a system with flat-rate tolls for each zone to a distance-based toll, where the toll is charged according to the mileage travelled (Figure 2-1-3). Previously, if a driver drove through flat-rate toll charging zones, it would be end up being an expensive toll, so drivers would get off the expressways right before the toll charging zones and use the bypass roads, making this one of the causes of traffic congestion on the bypass roads.

For example, if a driver entered the Yono on ramp in Saitama and drove to the Tomigaya exit in Tokyo, the driver would go through both the Saitama and the Tokyo flat-rate toll charging zones, amounting to a total charge of JPY1,100 in tolls. For this reason, many drivers would choose to use the Shinomiya bypass, which runs parallel to

Source) Ministry of Land, Infrastructure and Transport Social Infrastructure Development Council, Roads Subcommittee's 5th Land & Highway Panel (February 2013)

Figure 2-1-2 Changes in Traffic due to Discount

Source) Ministry of Land, Infrastructure, Transport and Tourism (MLIT) Social Infrastructure Development Council, Roads Subcommittee's 5th Land & Highway Panel (February 2013)

Source) MLIT Social Infrastructure Development Council, Roads Subcommittee's 5th Land & Highway Panel (February 2013)

the expressway without going through the toll-charging zones, causing traffic congestion on the Shinomiya bypass. However, when the toll-charging system changed to distance-based, the toll became JPY900 (JPY930 as of April 2014).