360 least-cost paths, pre-solved over OS Terrain 50. Move a dial to
see which landscape factors have to matter for a given corridor to emerge.
Cross-slope is a fourth factor; it was tested and changes almost nothing, so
it is held fixed.
Opens at the preferred setting — climb 14, wet 20,
crossing 2000, descent prior moderate — analyst judgements, not model outputs.
Cost of gaining and losing height. Turning this up drives the
route into the valleys — it trades wet ground for gentler grades.
Cost of level, low-lying ground — floodplain and marsh. Pushes
the route up onto dry chalk.
Charged per stream or river crossed. The strongest lever
here: from 13 crossings down to 1, and interfluve use from 17% to 46%.
New Town / Workway (N2) has a road drawn down the face on
Andrews & Dury 1773, a holloway with a 73 m drop on 1 m LIDAR, and usable
tracks on the ground today. Huish (N1) has none of these. The prior
discounts N2 and surcharges N1 across a 600 m catchment on the scarp, and
nowhere else.