Japanese Prime Minister Taro Aso's economic stimulus measures are about to unleash the nation's worst highway traffic jams..

Vacationers take a break at the Umihotaru rest area off the Tokyo Bay Aqua-Line highway, in Kisarazu, Chiba prefecture, Japan, on Sunday, April 26, 2009. Japanese Prime Minister Taro Aso's economic stimulus measures are about to unleash the nation's worst highway traffic jams, toll operators and police say.

Cars fill up the parking lot at the Ashigara service area off the Tomei Expressway in Oyama, Shizuoka pefecture, Japan, on Sunday, April 26, 2009

Vacationers exit the Umihotaru rest area off the Tokyo Bay Aqua-Line highway, in Kisarazu, Chiba prefecture, Japan, on Sunday, April 26, 2009.

Cars fill up the parking lot at the Ashigara service area off the Tomei Expressway in Oyama, Shizuoka prefecture, Japan, on Sunday, April 26, 2009.

Vacationers walk past tour buses parked in the lot of the Umihotaru rest area off the Tokyo Bay Aqua-Line highway, in Kisarazu, Chiba prefecture, Japan, on Sunday, April 26, 2009. Japanese Prime Minister Taro Aso's economic stimulus measures are about to unleash the nation's worst highway traffic jams, toll operators and police say

Cars are parked in a lot of the Umihotaru rest area off the Tokyo Bay Aqua-Line highway, in Kisarazu, Chiba prefecture, Japan, on Sunday, April 26, 2009. Japanese Prime Minister Taro Aso's economic stimulus measures are about to unleash the nation's worst highway traffic jams, toll operators and police say

A line of cars on the Tokyo Bay Aqua-Line highway wait to enter the parking lot of the Umihotaru rest area, in Kisarazu, Chiba prefecture, Japan, on Sunday, April 26, 2009. Japanese Prime Minister Taro Aso's economic stimulus measures are about to unleash the nation's worst highway traffic jams, toll operators and police say.

Vacationers take in a view of Mount Fuji at a service area off the Tomei Expressway, in Fuji, Shizuoka prefecture, Japan, on Sunday, April 26, 2009. Japanese Prime Minister Taro Aso's economic stimulus measures are about to unleash the nation's worst highway traffic jams, toll operators and police say.

Traffic streams along the Tomei Expressway and Route 1, in front of Mount Fuji in Shizuoka, Shizuoka prefecture, Japan, on Sunday, April 26, 2009. Japanese Prime Minister Taro Aso's economic stimulus measures are about to unleash the nation's worst highway traffic jams, toll operators and police say