The Need for Choice

There is no single best alignment.

Planning is subjective, and many issues are contentious. What value can be placed on ensuring that a freeway is kept out of sight of a scenic lookout? What is the social cost of land acquisition? The cost of an alignment intruding into private properties is not a simple function of the extent of the intrusion; extraneous (and frequently unquantifiable) costs such as legal proceedings, public relations, and delays have to be considered.

A calculation of the difference in construction costs between an alignment that intrudes and one that does not has to include these subjective factors when determining whether the intrusion is worth considering.

As an alternative, you can use the Quantm system to produce a selection of low-cost alignments that meet the objective criteria, and then allow planners (or the community) to select the alignment which represents the optimal balance between low-cost and, in their opinion, minimal adverse impacts. You can also customize that alignment if necessary.

For there to be a choice, there must be meaningful differences between the alignments produced. For instance, if you took the least cost-compliant alignment and moved one intersection point 1 mm, none of the many intervening alignments could be considered a real alternative to the first. Quantm’s optimization process ensures that the selection of low-cost alignments presented to the planner contains a range of genuine alternatives, rather than minor variations of a single least-cost solution.