## 3 Results  
### Minor Road, Major Road and Railways Infrastructure Movement  
A total of 70,406 PS points were analysed for minor roads, major roads, and railways across the six study areas. Western sites returned higher PS densities than Eastern sites in all infrastructure classes analysed, due to the study areas focusing predominantly on urban centers. Returned PS densities were highest for railways in all six study sites, with an average density of 18.23 PS targets returned per km of track, suggesting suitability of this infrastructure class for PSI analysis. Due to their relative widths, major roads--motorways buffered at 4 m, A-roads buffered at 3 m--returned a higher PS density than minor roads--B-roads and Minor-roads buffered at 2 m--returning 15.34 PS targets compared to 9.28 PS, respectively, per km of infrastructure. The resulting PSI velocity maps are shown in Figure 3. Overall PS densities highly varied across the six study sites. Urban areas such as Bristol and Bournemouth achieved a very high density of 3799 PS km\({}^{2}\) and 2058 PS km\({}^{2}\) respectively. Bath and Peterborough, which are an urban/rural mix attained only 795 and 730 PS km\({}^{2}\), respectively. As expected, the semi-rural study areas of Grantham and Kings Lynn achieved significantly less at 414 PS km\({}^{2}\) and 343 PS km\({}^{2}\), respectively. Figure 2: Daily Volumetric Water Content (VWC %) for the corresponding periods of PSI investigation for Western and Eastern England. VWC is measured at 10 cm depth from two in situ meteorological stations: Tadham Moor (Western England, 51.207099, \(-\)2.828639) is shown in red and Redmere (Eastern England, 52.443551, 0.433083) in blue. Railways exhibited the largest range of movement for all infrastructure types investigated, as depicted in Table 4. This is particularly so for Bath, where the average change in railway track level is not observed. Figure 3: Surface deformation map showing PSI values expressed as millimeters per year for the Six study areas. Dark red indicates subsidence of up to 30 mm year\({}^{-1}\) whilst Bright green indicates uplift of up to 30 mm year\({}^{-1}\). Insert map shows the location of the sites in the UK. was \(-2.59\) mm year\({}^{-1}\) (standard deviation \(5.38\) mm year\({}^{-1}\)) with Brown soils and Pelosols showing the highest rates of deformation. On average, railway tracks subside \(-0.88\) mm year\({}^{-1}\). However, cyclical patterns of infrastructure movement of greater velocities that \(0.88\) mm year\({}^{-1}\) were observed for Brown soils, Pelosols, Ground-water Gley soils and Surface-water Gley soils in Bristol, Grantham, Kings Lynn and Peterborough. Railways heave up to \(2.5\) mm for these major soil groups during winter months (December to April), and subside up to \(5\) mm during the summer months (April to September). Railways over Peat soils in Peterborough, exhibited the highest subsidence rate observed in this study, \(-7.5\) mm year\({}^{-1}\). As Table 5 highlights, a very small sample size of 113 PS points were analysed for railway tracks over Peat soils, so further investigation of this would be necessary to comment on these findings with confidence. Deformation of railways in Bath and Bournemouth present a linear pattern of deformation. Railway infrastructure in Bath is observed to subside when over Brown soils and Pelosols, whilst Bournemouth shows no deformation over Podzolic soils, as presented in Figure 4. No subsidence was detected for railways over Lithomorphic soils in Bath and Peterborough.