Work will begin this month on improvements to the Joetsu Shinkansen between Omiya and Niigata, which will reduce journey times by seven minutes, and this will take four years to complete. Combined with enhancements already underway between Ueno and Omiya, the improvements will reduce the fastest Tokyo - Niigata journey time from 1h 37min to 1h 29min. Currently most trains take more than two hours for the 301km trip.
Services on the Hokuriku Shinkansen will also benefit with a two-minute journey time reduction between Omiya and Takasaki.
The Yen 5bn ($US 45m) project primarily involves enhancing noise mitigation measures with the installation of 7km of additional noise barriers and raising 12km of existing barriers.
In March, JR East began introducing 12-car E7 series high-speed trains on the Joetsu Shinkansen to replace double-deck E4 series trains, which are being withdrawn. All services on the line will be operated by E7s by the end of 2022.
The infrastructure improvements will enable the new trains to operate at their 275km/h maximum commercial speed.