Smilaco mauritanicae-Querceto rotundifoliae S

6.1

Introduction

6.1.1 As outlined above it is proposed to re-develop the previously developed (brownfield) area of the site to provide a total of 225 dwellings. However, this represents the first phase of development on the site, as the site has been allocated for up to 350 dwellings in the Torfaen LDP. Therefore, this section of the report identifies the impact of the allocation (i.e. up to 350 dwellings) on the surrounding highway network, and identifies any mitigation measures required to reduce the impact of development generated traffic, should these be required.

6.1.2 As outlined in Section 1.0, the junctions to be assessed are as follows:

 Proposed site access on to Greenmeadow Way;

 Greenmeadow Way/Greenforge Lane/Ty Gwyn Way roundabout;

 Greenmeadow Way/Henllys Way priority junction;

6.2

Site access on to Greenmeadow Way

6.2.1 The operation of the proposed site access junction (see figure 4.3) has been assessed, for each of the assessment periods, using the TRL program Junction 8. The results of the analysis are presented in full in Appendix D, and summarised in Table 6.1 below.

Arm Base + development

Movement Am peak Pm peak

rfc Queue rfc Queue

2016

Site access B-AC 0.27 <1 veh. 0.19 <1 veh. Greenmeadow Way (s) C-AB 0.10 <1 veh. 0.15 <1 veh. 2026

Site access B-AC 0.28 <1 veh. 0.19 <1 veh. Greenmeadow Way (s) C-AB 0.10 <1 veh. 0.15 <1 veh. Table 6.1 Junction capacity analysis – access on Greenmeadow Way

6.2.2 It can be seen from the table above that the site access has sufficient capacity to accommodate the proposed development up to and including the 2026 ‘with development’ scenario, with a maximum rfc of 0.270 and a queue of less than one vehicle.

6.3

Greenmeadow Way/Greenforge Way/Ty Gwyn Way roundabout

6.3.1 The operation of the existing junction (see Figure 6.1) has been assessed, for each of the assessment periods, using the TRL program Junction 8. The results of the analysis are presented in full in Appendix E, and summarised in Table 6.2 below.

Arm Base + development

Am peak Pm peak Am peak Pm peak rfc Queue rfc Queue rfc Queue rfc Queue

2014

Greenforge Way 0.210 < 1 veh. 0.490 1 veh. St Dials Road 0.020 < 1 veh. 0.040 < 1 veh. Greenmeadow Way 0.220 < 1 veh. 0.230 < 1 veh. Ty Gwyn Way 0.450 1 veh. 0.230 < 1 veh. Greenmeadow Community Farm 0.030 < 1 veh. 0.040 < 1 veh. 2016

Greenforge Way 0.220 < 1 veh. 0.500 1 veh. 0.230 < 1 veh. 0.540 1 veh. St Dials Road 0.020 < 1 veh. 0.040 < 1 veh. 0.020 < 1 veh. 0.050 < 1 veh. Greenmeadow Way 0.230 < 1 veh. 0.240 < 1 veh. 0.270 < 1 veh. 0.270 < 1 veh. Ty Gwyn Way 0.460 1 veh. 0.240 < 1 veh. 0.480 1 veh. 0.250 < 1 veh. Greenmeadow Community Farm 0.030 < 1 veh. 0.040 < 1 veh. 0.030 < 1 veh. 0.040 < 1 veh. 2026

Greenforge Way 0.250 < 1 veh. 0.570 1 veh. 0.270 < 1 veh. 0.610 2 vehs. St Dials Road 0.020 < 1 veh. 0.050 < 1 veh. 0.020 < 1 veh. 0.070 < 1 veh. Greenmeadow Way 0.270 < 1 veh. 0.290 < 1 veh. 0.310 < 1 veh. 0.320 < 1 veh. Ty Gwyn Way 0.540 1 veh. 0.270 < 1 veh. 0.560 1 veh. 0.290 < 1 veh. Greenmeadow Community Farm 0.040 < 1 veh. 0.050 < 1 veh. 0.050 < 1 veh. 0.050 < 1 veh.

Table 6.2 Greenmeadow Way/Greenforge Lane/Ty Gwyn Way roundabout

6.3.2 It can be seen from the table above that the existing junction has sufficient capacity to accommodate the proposed development up to and including the 2026 ‘with development’ scenario, with a maximum rfc of 0.610 and a queue of two vehicles.

6.4

Greenmeadow Way/Henllys Way priority junction

6.4.1 The operation of the existing junction (see Figure 6.2) has been assessed, for each of the assessment periods, using the computer program LINSIG. The results of the analysis are presented in full in Appendix F, and summarised in

Table 6.3 below.

Arm Base Base + development

Am peak Pm peak

rfc Queue rfc Queue rfc Queue rfc Queue

2014

Greenmeadow Way - left 0.580 2 vehs. 0.380 1 veh. Greenmeadow Way - right 0.090 <1 veh. 0.080 <1 veh. Henllys Way - right 0.350 1 veh. 0.580 1 veh.

2016

Greenmeadow Way - left 0.600 1 veh. 0.390 1 veh. 0.730 3 vehs. 0.460 1 veh. Greenmeadow Way - right 0.100 < 1 veh. 0.080 < 1 veh. 0.170 <1 veh. 0.100 <1 veh. Henllys Way - right 0.360 1 veh. 0.590 1 veh. 0.440 1 veh. 0.670 2 vehs. 2026

Greenmeadow Way - left 0.760 3 vehs. 0.730 3 vehs. 0.910 7 vehs. 0.550 1 veh. Greenmeadow Way - right 0.230 < 1 veh. 0.160 < 1 veh. 0.630 1 veh. 0.200 <1 veh. Henllys Way - right 0.450 1 veh. 0.420 1 veh. 0.530 1 veh. 0.780 3 vehs.

Table 6.3 Junction capacity analysis – existing Greenmeadow Way/Henllys Way priority junction

6.4.2 It can be seen from the table above that the existing junction is predicted to operate above its practical reserve capacity in the ‘2026 with development’ scenario, with a maximum rfc of 0.910 and a maximum queue of seven vehicles.

6.4.3 In order to accommodate the additional traffic generated by the development, it is proposed to modify the existing junction (see Figure 6.3). The operation of the modified junction has been assessed, for each of the assessment periods, using the computer program LINSIG. The results of the analysis are also presented in full in Appendix F, and summarised in Table 6.4 over the page.

Arm Base + development

Am peak Pm peak rfc Queue rfc Queue

2016

Greenmeadow Way - left 0.700 2 vehs. 0.450 1 veh. Greenmeadow Way - right 0.130 <1 veh. 0.100 < 1 veh. Henllys Way - right 0.440 1 veh. 0.670 2 vehs. 2026

Greenmeadow Way - left 0.860 5 vehs. 0.530 1 veh. Greenmeadow Way - right 0.320 < 1 veh. 0.180 <1 veh. Henllys Way - right 0.530 1 veh. 0.780 3 vehs. Table 6.4 Junction capacity analysis – modified Greenmeadow Way/Henllys Way priority junction

6.4.4 It can be seen from the table above that the existing junction has sufficient capacity to accommodate the proposed development up to and including the 2026 ‘with development’ scenario, with a maximum rfc of 0.860 and a maximum queue of five vehicles.

6.5

Summary

6.5.1 The above analysis indicates that with the introduction of the proposed allocation (up to 350 dwellings) the existing Greenmeadow Way/Henllys Way junction will operate above its practical reserve capacity in the 2026 am peak period.

6.5.2 The analysis also demonstrates that the modified/proposed highway network has sufficient capacity to accommodate the predicted increases in demand (background growth and development generated traffic) in the 2026 am and pm peak periods.