An Examination of the Potential to Reduce the Cost of an Underground LRT Alignment through Geologic Planning and Technological Innovation : Phase I

The question of whether Twin Cities Metropolitan Region transportation needs should be served by fixed rail transit has been debated for many years. It appears that the issue may be approaching resolution as a result of the formation of the Regional Transit Board (RTB) and recent activity on the part of Hennepin County in forming a Regional Rail Authority and moving ahead with planning activity. Some important questions about light rail (LRT), such as the capacity of the system, are being answered, but others are not resolved. One of these is whether to site portions of a light rail system underground. While many decisionmakers endorse the worth of an underground alignment in at least the most densely developed urban areas, the cost versus benefit to construct underground versus a surface alignment has been an important factor.