Appendix a – Sestran Regional Model Option Assessment
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Appendix A – SEStran Regional Model Option Assessment 1. INTRODUCTION 1.1 Overview 1.1.1 This Appendix describes the SEStran Regional Model (SRM) outputs for the five defined scenario option tests. The definition of these scenario options and any associated modelling assumptions is described in the MLDP Options for Appraisal Note (SYSTRA, September 2010). 1.1.2 Each scenario option is compared with the MLDP Reference Case and the SEStran Regional Model Analysis Report (SYSTRA, September 2010) provides a summary of the Midlothian LDP model analysis, which has been undertaken using the SRM. This document also includes a summary of the SRM, and the definition of the assumed MLDP land-use scenario, which is common in all the scenario option tests. 1.2 Model Dimensions 1.2.1 The SRM demand model contains 470 zones from which traffic and travel (both road and PT based) originates and destinates. Where 16 zones make up Midlothian in the demand and PT models, this is expanded to 27 zones for the road model. This allows for a better representation of the traffic movements within the Midlothian area with the inclusion of additional network detail. 1.2.2 The SRM is representative of average weekday travel movements within which the following time periods are modelled: Average weekday (AM) morning peak hour: 07:00-10:00; and Average weekday (IP) inter peak hour: 10:00-16:00; and Average weekday (PM) evening peak hour: 16:00-19:00. 1.2.3 Individual factors are applied by mode and time period to create an ‘average’ peak hour. For the purposes of appraising the MLDP scenario options, modelled outputs from AM and PM peak hours have been analysed where the transport impacts are greatest. Interpeak hour model outputs are available. 1.2.4 The road assignment model includes five assigned vehicle types and journey purposes as follows: Car In-Work; Car Non-Work Commuter; Car Non-Work Other; LGV; and HGV. 1.2.5 The PT assignment model includes three assigned PT purposes as follows: PT In-Work; Car Non-Work Commuter; and Car Non-Work Other. Appendix A – SEStran Regional Model Option Assessment 1.3 Key Performance Indicators 1.3.1 The KPIs for the MLDP, as described in Chapter 1, include a wide range of metrics, not all of which can be measured using the SRM as part of the MLDP appraisal, or that are directly relevant when identifying issues and appraising options. Therefore, the following indicators have been used when undertaking the LDP appraisal using the SRM: Travel Demand (AM and PM peak periods): PT mode share; and Park and Ride site occupancies. Network Demand (AM and PM peak hours): vehicle kilometres on key corridors in study area (A68, A7, A701, A702, A703, A720); and passenger kilometres on key corridors in study area (A68, A7, A701, A702, A703, A720, Waverley Rail Line). Road Network Operation (AM and PM peak hours): average vehicle speeds on key corridors in study area; delays at junctions (total and per vehicle); ratio of (traffic) flow to capacity (RFC); car journey times along main Midlothian corridors; PT journey times to/from Edinburgh city centre; estimated annual vehicle carbon emissions; and estimated annual accident numbers using standard accident rates. 1.4 Sector System 1.4.1 For the purposes of analysing the LDP scenario options, a matrix sector system has been prepared as shown in Figure 1 and Table 1. A sector system combines a number of zones together for the purpose of reporting. This sector system represents Midlothian via 10 sectors and aggregates the other local authorities. In addition to these, the external trips (all movements to\from outwith the SRM area) have been included in a single sector and the park & ride sites have been aggregated into a single sector. A2 Appendix A – SEStran Regional Model Option Assessment 14 12 13 1 10 8 9 15 7 3 5 6 2 4 11 11 Figure 1. Midlothian Sector Map Table 1. SRM Sector System SECTOR DESCRIPTION SECTOR DESCRIPTION 1 Shawfair and Danderhall 11 The Borders 2 Gorebridge 12 North Edinburgh 3 Roslin/Bilston 13 South Edinburgh 4 Penicuik 14 East Lothian 5 Rosewell 15 West Lothian 6 Newtongrange 16 West 7 Mayfield 17 Fife 8 Loanhead 18 Externals 9 Bonnyrigg 19 Park and Ride 10 Dalkeith A3 Appendix A – SEStran Regional Model Option Assessment 1.5 Model Corridors 1.5.1 As well as matrix sectors, groupings of road links have been defined as corridors for reporting of key link attributes and this is illustrated in Figure 2. Figure 2. Strategic Corridors A4 Appendix A – SEStran Regional Model Option Assessment 1.6 Car Journey Time Routes 1.6.1 For each scenario option a selection of journey time routes have been analysed on the two key corridors towards Edinburgh through Midlothian, as shown in Figure 3. Figure 3. Journey Time Route Map A5 Appendix A – SEStran Regional Model Option Assessment 2. SCENARIO 1: SITE HS1 (S2) NEW ACCESS 2.1 Overview 2.1.1 Site Hs1 (S2) is a development at Newton Farm, near Shawfair. A total of 480 dwellings are proposed for this site by 2024. In the reference case, these dwellings connect to the road network via the B6415 Old Craighall Road. For this scenario option, the Hs1 development is connected to the A720/A68 interchange via a new access arm to the West of the junction. In order to model the traffic associated with the Hs1 site, the number of trips with an origin or destination in the original zone (Zone 251) within which Hs1 lies, require to be split. These trips have been taken away from the original zone and added to the new zone. The volume of trips have been estimated based on the proportion of households. This excludes intra-zonal’ trips within the Shawfair zone which have not been changed in this scenario option that focusses on strategic traffic movements. 2.2 Vehicle Distance by Key Corridor 2.2.1 The modelled annual vehicle distance (in kilometres) has been evaluated on a corridor basis (see Figure 2 for the reference to corridors). Table 2 presents the estimated annualised vehicle kms for Scenario 1 compared against the MLDP Reference Case. Table 2. Scenario 1 Annualised Vehicle KMs By Key Corridor (1,000’s) CORRIDOR REFERENCE CASE SCENARIO CHANGE 1 A720 246,570 246,490 -80 -0.03% 2 A702 21,320 21,310 -10 -0.05% 3 A701 23,020 23,010 -10 -0.04% 4 A7 44,400 44,430 30 -0.07% 5 A68 29,670 29,680 10 -0.03% 2.2.2 Key findings: This scenario results in a very slight reduction in vehicle distance on the strategic road network. A6 Appendix A – SEStran Regional Model Option Assessment 2.3 Network Performance 2.3.1 The following series of Figures illustrate the change in road network performance for Scenario 1 compared against the MLDP Reference Case. Figure 4. Scenario 1 AM Junction Delays Figure 5. Scenario 1 PM Junction Delays A7 Appendix A – SEStran Regional Model Option Assessment Figure 6. Scenario 1 AM Volume to Capacity Ratio Figure 7. Scenario 1 PM Volume to Capacity Ratio 2.3.2 Key findings: the loading of site Hs1 strategic traffic via the A720/A68 junction does not present any issues at this or adjacent junctions and has a relatively minor impact on the strategic road network performance. A8 Appendix A – SEStran Regional Model Option Assessment 2.4 Average Vehicle Speeds 2.4.1 Table 3 and Table 4 present the network average speeds for Scenario 1 compared against the MLDP Reference Case for the AM and PM peak hours respectively. This analysis is restricted to the modelled Midlothian area only. Table 3. Scenario 1 AM Average Vehicle Speeds CORRIDOR REFERENCE SCENARIO CHANGE CASE 1 A720 43.8 43.6 -0.2 -0.5% 2 A702 61.4 61.4 0 0% 3 A701 41.4 41.7 0.3 0.7% 4 A7 62.4 62.3 -0.1 -0.2% 5 A68 71.0 71.0 0 0% Local Roads in - 48.3 47.4 -0.9 -1.9% Midlothian Midlothian 47.5 47.1 -0.4 -0.8% Table 4. Scenario 1 PM Average Vehicle Speeds CORRIDOR REFERENCE SCENARIO CHANGE CASE 1 A720 50.8 50.9 0.1 0.2% 2 A702 61.9 62.0 0.1 0.2% 3 A701 41.9 41.8 -0.1 -0.2% 4 A7 58.1 58.0 -0.1 -0.2% 5 A68 71.7 71.6 -0.1 -0.1% Local Roads in - 47.3 47.3 0 0% Midlothian Midlothian 49.2 49.3 0.1 0.2% 2.4.2 Key findings: this scenario shows little impact on the strategic road network in either the AM or PM peak hours with some minor increases and decreases in average vehicle speeds. A9 Appendix A – SEStran Regional Model Option Assessment 2.5 Estimated Annual Vehicle Carbon Emissions 2.5.1 Based on the insignificant changes in annualised vehicle kilometres, there is anticipated to be no significant change in annual vehicle carbon emissions. 2.6 Estimated Annual Accident Numbers 2.6.1 Based on the insignificant changes in annualised vehicle kilometres, there is anticipated to be no significant change in annual accident numbers. A10 Appendix A – SEStran Regional Model Option Assessment 3. SCENARIO 2: LOCAL JUNCTION CAPACITY RELIEF 3.1 Overview 3.1.1 This scenario option models potential capacity relief measures at the following junction locations: 1. A702/ A703/ Damhead MOVA Optimisation 2. A702/ Mauricewood Road Roundabout 3. A701/ Pentland Road/ Damhead MOVA Optimisation 4.