SAN FRANCISCO - A federal judge said Tuesday that the Bush administration had the right to overturn a ban on road construction in untouched parts of the national forests but questioned whether it could do so without weighing the possible environmental effects.U.S. District Judge Elizabeth Laporte said the Forest Service appeared to be “on solid ground" last year when it reversed a Clinton administration rule banning new roads on nearly a third of federal forests.But she questioned whether the agency violated federal law by skipping environmental studies - the heart of two lawsuits brought by 20 environmental groups and California, Oregon, New Mexico and Washington. The cases have since been consolidated, and all parties presented arguments Tuesday in Laporte's courtroom. .