Advanced optimization methods for road construction

道路建设是支撑高效道路网络的重要组成部分。高质量公路每公里的造价高达2000万美元，而森林公路每公里的造价为1000万至100万美元，在保持安全标准的同时降低道路建设成本是非常可取的。道路设计也变得越来越复杂。它现在必须考虑到环境影响、减轻自然或人为灾害的影响。无论是在加拿大还是在任何发达国家，减少道路建设费用可能在控制未来预算和维持生活质量方面发挥重要作用。道路设计问题通常分为三个子问题。首先，水平对齐考虑了潜在道路站点的卫星视图，选择了几个备选的走廊，并确定了走廊内的确切路径。接下来，垂直路线考虑要切割哪个山丘或填哪个沟壑，以建造一条穿过水平路线的道路，同时满足安全和法规约束。最后，土移问题考虑的是要移动多少物质才能实现目标的垂直对准。我们的目标是自动化大部分当前的手工过程，以节省设计工程师在计算任务上的时间，这样他就可以集中精力考虑尽可能多的约束条件。**我们计划将整个道路设计过程从走廊选择到土方决定完全自动化。我们的方法侧重于改善求解垂直对齐模型的计算时间，以便我们可以执行广泛的搜索最便宜的水平对齐。我们将在当前模型中加入额外的功能，以更精确地反映构建过程。虽然目前最先进的优化求解器无法解决完整的问题，但最新的优化算法与仔细的近似相结合，将提供更便宜的道路设计，允许工程师考虑更广泛的替代路径，并提供对解决方案鲁棒性的洞察。由此产生的模型和算法将在商业道路设计软件中实施和部署，并广泛使用

Road construction represents a significant portion of supporting an efficient road network. Highway quality roads cost as much as $20 million per km while forestry roads costs from $1,000 to $1 million per km. Reducing road construction costs while maintaining safety standards is very desirable. Road design has also become increasingly more complex. It now has to take into account environmental impact, mitigation of the impact of natural or man-made disasters. Reducing road construction costs may play a major role in controlling future budgets and maintaining quality of life, both in Canada and in any developed country. ** The road design problem is usually split into three subproblems. First, the horizontal alignment considers a satellite view of the potential road site, selects a handful of corridor alternatives, and determines the exact path within that corridor. Next the vertical alignment considers which hill to cut or ravine to fill to build a road that goes through the horizontal alignment while satisfying safety and regulation constraints. Finally, the earth moving problem considers how much material to move to realize the target vertical alignment. Our goal is to automate much of the current manual process to save design engineers time on computational tasks so (s)he can concentrate on considering as many constraints as possible.** We plan to fully automate the full road design process from corridor selection to earthmove decisions. Our approach focuses on improving computation time to solve the vertical alignment model so we can perform an extensive search for the cheapest horizontal alignment. We will incorporate additional features into current models to more precisely reflect the building process. While the complete problem is out of reach of current state-of-the-art optimization solvers, the latest optimization algorithms coupled with carefully approximation will provide much chearper road designs, allow engineers to consider a wider range of alternative paths, and provide insight into the robustness of the solution. The resulting models and algorithms will be implemented and deployed in a commercial road design software, and made widely available.**