A truck accident on Interstate 84 between Cascade Locks and Hood River this morning led to approximately 2,500 gallons of diesel being leaked onto the highway.  According to the Oregon State Police, a preliminary investigation shows a Space Age semi-tractor pulling two tanker trucks was eastbound on I-84 near milepost 54.  The OSP says the driver, 34-year-old James Altman of Portland, was driving too fast for the snowy conditions on the roadway at about 10:30 Monday morning.   Altman lost control of the commercial motor vehicle and the tankers flipped onto their sides.  When the tankers flipped they started leaking onto the diesel onto the highway.   The diesel eventually seeped underneath the barrier onto the westbound lanes of travel.  Two tanks completely spilled their diesel.  Space Age has contracted a company to clean-up the spill and tows are on scene.  The Oregon Department of Transportation and the Oregon Emergency Response System were notified and were going to the scene to assist.