Global Routing has been a traditional EDA problem. It has congestion elimination as the first and foremost priority. Despite of the recent development for popular rip-up and reroute framework, the congestion elimination process remains arbitrary and requires significant tunings. In order to achieve more consistent congestion elimination, we propose a new preprocessing framework for global routing. In the framework, we first identify the most congested global routing locations by an interval overflow lower bound technique. Then we use auction based detour algorithm to compute which nets and where to detour. The framework can be applied to any global router and would help them to achieve significant improvement in both solution quality and runtime.