About the Companion Website xv 1 The Transportation Planning Process 1 1.1 Why Are Highways So Important? 1 1.2 The Administration of Highway Schemes 1 1.3 Sources of Funding 2 1.4 Highway Planning 3 1.4.1 Introduction 3 1.4.

2 Travel Data 4 1.4.3 Highway Planning Strategies 6 1.4.3.1 Land-Use Transportation Approach 6 1.4.3.

2 The Demand Management Approach 6 1.4.3.3 The Car-Centred Approach 7 1.4.3.4 The Public Transport-Centred Approach 7 1.4.

4 Transportation Studies 7 1.4.4.1 Transportation Survey 7 1.4.4.2 Production and Use of Mathematical Models 8 1.5 The Decision-Making Process in Highway and Transport Planning 8 1.

5.1 Introduction 8 1.5.2 Economic Assessment 10 1.5.3 Environmental Assessment 11 1.5.4 Public Consultation 12 1.

6 Summary 13 References 13 2 Forecasting Future Traffic Flows 15 2.1 Basic Principles of Traffic Demand Analysis 15 2.2 Demand Modelling 16 2.3 Land-Use Models 18 2.4 Trip Generation 18 2.4.1 TRICS ® Database 23 2.5 Trip Distribution 24 2.

5.1 Introduction 24 2.5.2 The Gravity Model 25 2.5.3 Growth Factor Models 30 2.5.4 The Furness Method 31 2.

6 Modal Split 36 2.7 Traffic Assignment 41 2.8 A Full Example of the Four-Stage Transportation Modelling Process 46 2.8.1 Trip Production 46 2.8.2 Trip Distribution 47 2.8.

3 Modal Split 50 2.8.4 Trip Assignment 52 2.9 ''Decide and Provide'' Versus ''Predict and Provide'' 53 2.10 Concluding Comments 54 Additional Problems 54 References 57 3 Scheme Appraisal for Highway Projects 59 3.1 Introduction 59 3.2 Economic Appraisal of Highway Schemes 60 3.3 Cba 61 3.

3.1 Introduction 61 3.3.2 Identifying the Main Project Options 61 3.3.3 Identifying all Relevant Costs and Benefits 62 3.3.3.

1 Reductions in VOCs 63 3.3.3.2 Savings in Time 63 3.3.3.3 Reduction in the Frequency of Accidents 64 3.3.

4 Economic Life, Residual Value, and the Discount Rate 64 3.3.5 Use of Economic Indicators to Assess Basic Economic Viability 65 3.3.6 Highway CBA Worked Example 67 3.3.6.1 Introduction 67 3.

3.6.2 Computation of Discounted Benefits and Costs 68 3.3.6.3 Npv 70 3.3.6.

4 Benefit-Cost Ratio 70 3.3.6.5 Irr 70 3.3.6.6 Summary 70 3.3.

7 Coba 70 3.3.8 Advantages and Disadvantages of CBA 71 3.4 Payback Analysis 73 3.5 Environmental Appraisal of Highway Schemes 75 3.6 The New Approach to Appraisal 80 3.6.1 Environment 81 3.

6.1.1 Noise 81 3.6.1.2 Local Air Quality 81 3.6.1.

3 Landscape 82 3.6.1.4 Biodiversity 82 3.6.1.5 Heritage 82 3.6.

1.6 Water 82 3.6.1.7 Safety 83 3.6.1.8 Economy 83 3.

6.1.9 Journey Times and VOCs 83 3.6.1.10 Costs 83 3.6.1.

11 Reliability 83 3.6.1.12 Regeneration 83 3.6.1.13 Accessibility 84 3.6.

1.14 Pedestrians, Cyclists, and Equestrians 84 3.6.1.15 Access to Public Transport 85 3.6.1.16 Community Severance 85 3.

6.1.17 Integration 85 3.7 NATA Refresh 86 3.7.1 Changes to the AST 86 3.7.2 Enhanced Presentation of Monetary Impacts 87 3.

7.3 More Detailed Relationship Between Benefit-Cost Ratio and Value for Money 87 3.8 Transport Analysis Guidance: The Transport Appraisal Process 87 3.9 Project Management Guidelines 89 3.10 Common Appraisal Framework for Transport Projects and Programmes 90 3.11 Summary 91 References 91 4 Basic Elements of Highway Traffic Analysis 93 4.1 Introduction 93 4.2 Surveying Road Traffic 93 4.

2.1 Introduction 93 4.2.2 Vehicle Surveys 94 4.2.2.1 Introduction 94 4.2.

2.2 Manual Counts 94 4.2.2.3 Automatic Counts 94 4.2.3 Speed Surveys 95 4.2.

4 Delay/Queuing Surveys 96 4.2.5 Area-Wide Surveys 96 4.2.5.1 Introduction 96 4.2.5.

2 Roadside Interview Surveys 97 4.2.5.3 Self-Completion Forms 97 4.2.5.4 Registration Plate Surveys 97 4.3 Journey Speed and Travel Time Surveys 98 4.

3.1 Introduction 98 4.3.2 The Moving Observer Method 98 4.4 Speed, Flow, and Density of a Stream of Traffic 103 4.4.1 Speed-Density Relationship 103 4.4.

2 Flow-Density Relationship 104 4.4.3 Speed-Flow Relationship 105 4.5 Headway Distributions in Highway Traffic Flow 109 4.5.1 Introduction 109 4.5.2 Negative Exponential Headway Distribution 110 4.

5.3 Limitations of the Poisson System for Modelling Headway 114 4.6 Queuing Analysis 114 4.6.1 Introduction 114 4.6.2 The D/D/1 Queuing Model 114 4.6.

3 The M/D/1 Queuing Model 118 4.6.4 The M/M/1 Queuing Model 119 4.6.5 The M/M/N Queuing Model 120 Additional Problems 123 References 128 5 Determining the Capacity of a Highway 129 5.1 Introduction 129 5.2 The ''Level of Service'' Approach Using the Transportation Research Board 129 5.2.

1 Introduction 129 5.2.2 Some Definitions 131 5.2.3 Maximum Service Flow Rates for Multilane Highways 131 5.2.4 Maximum Service Flow Rates for Two-Lane Highways 137 5.2.

5 Sizing a Road Using the Highway Capacity Manual Approach 140 5.3 The 2010 Highway Capacity Manual - Analysis of Capacity and Level of Service for Multi-Lane and Two-Lane Highways 143 5.3.1 Introduction 143 5.3.2 Capacity and Level of Service of Multilane Highways (2010 Highway Capacity Manual) 143 5.3.2.

1 Flow Characteristics Under Base Conditions 143 5.3.2.2 Capacity of Multilane Highway Segments 144 5.3.2.3 Level of Service (LOS) for Multilane Highway Segments 144 5.3.

2.4 Required Data for the LOS Computation 144 5.3.2.5 Computing LOS for a Multilane Highway 145 5.3.3 Capacity and Level of Service of Two-Lane Highways 150 5.3.

3.1 Flow Characteristics Under Base Conditions 150 5.3.3.2 Capacity and Level of Service 150 5.3.3.3 Required Input Data and Default Values 151 5.

3.3.4 Demand Volumes and Flow Rates 152 5.3.3.5 Computing LOS and Capacity for a Two-Lane Highway 152 5.3.3.

6 Determining Level of Service for Class 1 Two-Lane Highways 154 5.3.3.7 Determining the Level of Service for Class 2 Two-Lane Highways 161 5.3.3.8 Determining the Level of service for Class 3 Two-Lane Highways 166 5.4 The 2016 Highway Capacity Manual - Analysis of Capacity and Level of Service for Multi-Lane Highways 167 5.

4.1 Introduction 167 5.4.2 Capacity and Level of Service of Multilane Highways (2016 Highway Capacity Manual) 167 5.4.2.1 Speed Versus Flow 167 5.4.

2.2 Baseline Conditions and Capacity 167 5.4.2.3 Determining Free-Flow Speed 168 5.4.2.4 Determination of Incident Flow Rate 168 5.

4.2.5 Calculation of Density and Determination of Level of Service 168 5.5 The UK Approach for Rural Roads 170 5.5.1 Introduction 170 5.5.2 Estimation of AADT for a Rural Road in Its Year of Opening 171 5.

6 The UK Approach to Urban Roads 173 5.6.1 Introduction 173 5.6.2 Forecast Flows on Urban Roads 174 5.7 Expansion of 12- and 16-Hour Traffic Counts into AADT Flows 177 5.8 Concluding Comments 178 Additional Problems 179 References 181 6 The Design of Highway Intersections 183 6.1 Introduction 183 6.

2 Deriving DRFs from Baseline Traffic Figures 184 6.2.1 Existing Junctions 184 6.2.2 New Junctions 184 6.2.3 Short-Term Variations in Flow 184 6.2.

4 Conversion of AADT to Highest Hourly Flows 185 6.3 Major/Minor Priority Intersections 185 6.3.1 Introduction 185 6.3.2 Equations for Determining Capacities and Delays 189 6.3.3 Geometric Layout Details 196 6.

3.3.1 Horizontal Alignment 196 6.3.3.2 Vertical Alignment 196 6.3.3.

3 Visibility 196 6.3.3.4 Dedicated Lane on the Major Road for Right-Turning Vehicles 196 6.4 Roundabout Intersections 197 6.4.1 Introduction 197 6.4.

2 Types of a Roundabout 199 6.4.2.1 Mini-Roundabout 199 6.4.2.2 Normal Roundabout 200 6.4.

2.3 Double Roundabout 200 6.4.2.4 Other Forms 201 6.4.3 Traffic Capacity at Roundabouts 203 6.4.

3.1 Drf 205 6.4.4 Geometric Details 209 6.4.4.1 Entry Width 209 6.4.

4.2 Entry Angle 209 6.4.4.3 Entry Radius 209 6.4.4.4 Entry Deflection/Entry Path Radius 210 6.

4.4.5 Icd 210 6.4.4.6 Circulatory Carriageway 210 6.4.4.

7 Main Central Island 210 6.5 Basics of Traffic Signal Control: Optimisation and Delays 210 6.5.1 Introduction 210 6.5.2 Phasing at a Signalised Intersection 212 6.5.3 Saturation Flow 212 6.

5.4 Effective Green Time 217 6.5.5 Optimum Cycle Time 217 6.5.6 Average Vehicle Delays at the Approach to a Signalised Intersection 220 6.5.7 Average Queue Lengths at the Approach to a Signalised Intersection 222 6.

5.8 Signal Linkage 223 6.6 Concluding Remarks 228 Additional Problems 228 References 230 7 Geometric Alignment and Design 233 7.1 Basic Physical Elements of a Highway 233 7.1.1 Main Carriageway 233 7.1.2 Central Reservation 233 7.

1.3 Hard Shoulders/Hard Strips/Verges 234 7.2 Design Speed and Stopping and Overtaking Sight Distances 237 7.2.1 Introduction 237 7.2.2 Urban Roads 238 7.2.

3 Rural Roads 239 7.2.3.1 Statu.