## 3 Results
### FACPPs and Trajectories Deviations  
Deviations (in m) of FACPPs constructed according to the A-2 approach from FACPPs constructed according to the A-1 approach for every R and at every cross-section are shown in Figure 6.  
The largest deviations (which do not exceed 0.40 m) for roundabouts with small outer radii are noted at cross-sections 3 and 11 (Figure 6). With an increase in R, a decrease in deviations is noted, as the cross-sections with maximum deviation become cross-sections closer to the circulatory roadway entry and exit (2 and 12). Deviations under 0.05 m are noted at cross-sections 1, 5-9, and 13. This was expected for cross-section 7 because it transverses point B, which is a common point for analyzed paths. Deviations are proportional to the outer radius R at cross-sections 1, 2, 12, and 13, and inversely proportional at cross-sections 3-11. Deviations (in m) of the chassis right-hand-side trajectory for every R and at every cross-section are shown in Figure 7.  
Figure 5: Cross-sections and investigated envelopes and paths. The largest deviations (which do not exceed 0.35 m) for roundabouts with small outer radii are again noted at cross-sections 3 and 11 (Figure 7). Meanwhile, at roundabouts with outer radii of 13.0, 13.5, and 14.0 m, larger deviations are noted at cross-section 4. With an increase in R, a decrease in deviations is noted. Cross-section 3 remains the one with maximum deviations on the circulatory roadway entry, while cross-section 12 becomes the one with maximum deviations on the circulatory roadway exit. Deviations under 0.05 m are noted at cross-sections 5-9 and 13. This was expected for cross-section 7 because it transverses point B, which is a common point for analyzed paths. Deviations are proportional to the outer radius R at cross-section 12 and inversely proportional at cross-sections 1-11 and 13. Deviations (in m) of the design vehicle body right-hand-side trajectory for every R and at every cross-section are shown in Figure 8.  
Figure 6: FACPP deviations. Figure 7: Chassis right-hand-side trajectory deviations. The largest deviations (which do not exceed 0.40 m) are noted at cross-sections 4 and 11 for roundabouts with small outer radii. With an increase in R, a decrease in deviations is noted, as the cross-sections with maximum deviation become cross-sections closer to the circulatory roadway entry and exit (3 and 11). Deviations under 0.05 m are noted at cross-sections 5-9 and 13. This was expected for cross-section 7 because it transverses point B, which is a common point for analyzed paths. Deviations and outer radii, R, are proportional at cross-sections 3, 12, and 13, and inversely proportional at cross-sections 1 and 4-11. Deviations (in m) of chassis left-hand-side trajectory for every R and at every cross-section are shown in Figure 9.  
The largest deviations (which do not exceed 0.30 m) are noted at cross-section 2. With an increase in R, a decrease in deviations is noted at cross-sections 3-13. Deviations under 0.05 m are noted at cross-section 1 for all R and on cross-sections 5-7 for larger radii. The biggest influence of R on deviations is noted for cross-sections 3-9, where deviations vary from under 0.05 to over 0.15 m. At the same time, deviations are inversely proportional to the outer radius R at these cross-sections. Figure 8: Body right-hand-side trajectory deviations. Figure 9: Chassis left-hand-side trajectory deviations. Deviations (in m) of the design vehicle body left-hand-side trajectory for every R and at every cross-section are shown in Figure 10.  
The largest deviations (which do not exceed 0.25 m) are noted at cross-sections 2 (for larger R) and 3 (for R between 13.0 and 14.5 m). Deviations are inversely proportional to the outer radius, R, at cross-sections 3-13. Deviations under 0.05 m are noted at cross-section 1 for all R and on cross-sections 5-7 for larger radii.