Design Report Guideline
Table of Contents
- 1. Purpose of Guideline
- 2. Terminology
- 3. Structure of Report
- 4. Cover Page
- 5. Document Release Information
- 6. Table of Contents
- 7. Body of the Report
- 7.1 Introduction
- 7.2 Background
- 7.3 Design Standards
- 7.4. Design
- 7.5. Services
- 7.6. Geotechnical Investigation
- 7.7. Structures
- 7.8. Landscape Design
- 7.9. Environmental
- 7.10. Land Requirements
- 7.11. Construction, Maintenance and Traffic Management
- 7.12. Cost Estimate
- 7.13. Issues to be Resolved
- 7.14. Recommendations
- 7.15. Conclusion
- 8. Appendices
1. Purpose of Guideline
This guideline is intended to provide assistance when preparing a design report for a road design project.
Design reports are produced at various stages (phases) in the development of the design. These phases involve particular design objectives and varying degrees of design detail; from the concept phase through to the final design phase for the road construction.
The report will vary in content depending on the particular design phase (e.g. concept, preliminary or final design), the project type (e.g. new construction, carriageway duplication, road widening, etc.) and the works required to be undertaken (e.g. drainage, landscaping, electrical works, etc.). Other types of work such as bridge and structural design may have separate reporting requirements.
In general the report will define the scope (extent) of the project, specify the design standards adopted for the project, discuss and summarise the design considerations including any alternatives, and identify associated issues.
This guideline is not intended to be exhaustive but seeks to bring to the attention of the author of the report the desirable content that should be included in a design report.
2. Terminology
The terminology used in this guideline is consistent with Main Roads Glossary of Technical Terms (Document No. D11#319277) and Austroads Glossary of Terms 2015 (Document No. AP-C87-15).
3. Structure of Report
In general the design report should be structured as follows:
- Cover page
- Document release information
- Table of contents
- Body of the report
- Appendices
The file name is to be shown on all pages.
The page number is to be shown on the RHS of all pages except cover page
4. Cover Page
The cover page should include the following details:
- Main Roads Western Australia
- Road Name or Project Name
- Road Section
- S.L.K. - S.L.K.
- Local Authority Name (and Number)
- Design Report (preceded by the phase e.g. Concept, Preliminary or Final)
- Report Status (Draft / Final)
- Project Number and Contract Number (if relevant)
- Date (Month / Year)
5. Document Release Information
The document release information page should specify the following details:
- The author's company name, street address, city, state, postcode, telephone number, facsimile number and e-mail address.
- The document ownership and use.
- The document status including; the revision number, the author, the reviewer and approval for issue.
- Distribution list (list of people to whom the report has been sent e.g. Project Manager, etc.).
- File number (Main Roads and/or Consultant).
- Project Number (Main Roads and/or Consultant).
6. Table of Contents
This table lists the primary headings and sub-headings of the 'Body of the Report' and includes reference to the 'Appendices' section of the design report.
7. Body of the Report
This section is the substance of the design report and may include the following information:
7.1 Introduction
The introduction to the design report will be a concise statement defining who commissioned the design project, a description of the road under consideration, the scope of the design work undertaken, the reason(s) for undertaking the project and what benefits are expected to be achieved as a result of the design.
For some reports, an Executive Summary may be required.
7.2 Background
The background section of the report will include reference to previous reports or work undertaken and other relevant information used to supplement the design input or information which affected the design standards. This will include the following:
7.2.1 TopographyThis will provide a description of the terrain within the road corridor for sections of the road alignment e.g. flat, rolling, hilly, mountainous etc.
7.2.2 Road Reserve
This will provide a description of the existing road reserve width, the proposed road reserve width, reference to applicable regional schemes and Main Roads land schedules.
7.2.3 Traffic Assessment and Forecast
Traffic counts which are applicable to the design project may be included in the 'Appendices' section of the report. Traffic figures generated from the traffic counts are presented as number of vehicles/day, in each direction. Traffic forecast results will show the estimated increase or decrease in traffic volumes as number of vehicles/day, in each direction. As appropriate, reference should be made to the percentage of the total traffic comprising local traffic and the remaining percentage being through traffic. The percentage of heavy vehicles as a percentage of the total traffic should also be shown.
Comment should be made as to whether there was any further seasonal adjustment/consideration given to the volumes recorded and used.
A copy of the traffic report and a summary of recommendations should be included in the 'Appendices' section, if applicable.
7.2.4 Crash History
A summary of the crash history for the applicable road section is to be provided. The summary may include:
- the number of crashes requiring medical treatment and/or hospitalisation,
- the number of fatalities,
- the percentage of crashes that occurred on curves and sloped gradients
- the percentage of rear end crashes,
- the percentage of head on crashes,
- the percentage of sideswipe - same direction type crashes,
- a statement attributing the statistics to a probable cause e.g. lack of overtaking opportunities and driver frustration,
- and the percentage of crashes related to collisions with animals.
A copy of the crash statistics may be included in the 'Appendices' section of the report.
7.2.5 ROSMA Road Trauma Reduction
Projects should aim to improve the safety of the road environment.
A ROSMA (Road Safety Management) assessment should be undertaken using the crash history obtained to identify safety issues then select and evaluate treatments.
This process is described in detail in the Main Roads Road Safety Branch website.
A list of possible treatments along with KSI crash reduction estimates may be obtained from the Road Trauma Treatments Guideline.
A Trim folder reference should be provided for the location of the ROSMA Road Trauma Reduction Report.
7.2.6 Road Safety Audits
A copy of any Road Safety Audits previously undertaken and a summary of recommendations should be included in the 'Appendices' section, if applicable.
7.2.7 Survey
This will specify:
- the type of survey used for the project e.g. field detail pickup or photogrammetry,
- the accuracy of the survey (horizontally and vertically),
- the date the survey was undertaken,
- the grid coordinate system used e.g. PCG94,
- and whether further survey is required for later design phases.
A Metadata statement in accordance with Main Roads Survey and Mapping Data Management Standards should be included in the 'Appendices' section.
7.2.8 Cadastral
This will specify:
- the source of the cadastral information e.g. DOLA,
- the extent of cadastral information e.g. lot boundaries and the MRS reservation,
- the accuracy of the data,
- and the date at which the data is considered to accurately reflect the legal cadastral status (due to cadastral information being dynamic in nature).
7.2.9 Services
This will specify:
- the source of the services information e.g. 'DIAL BEFORE YOU DIG Services',
- a description of the authorities who provided the services information e.g. Western Power, Alinta Gas, Telstra, Watercorp, etc.,
- a description of the type and size of services or a plan showing same e.g., 200 dia. steel gas main, optic fibre cable, etc.,
- and the date at which the data was considered current.
7.2.10 Geotechnical
This will document references to previous geotechnical investigations and reports relevant to the design.
7.2.11 Environmental
This will document references to previous environmental studies and reports relevant to the design.
7.2.12 Planning Studies
This will document references to previous concept development reports, planning strategies and studies relevant to the design.
7.3 Design Standards
This section of the design report will document the Main Roads design standards adopted for the project, or project specific design standards, and the reasons for any departures from these standards. The design standards are generally specified in the project brief that is provided to the Designer. An explanation should also be provided where a project specific design standard is adopted in-lieu of a standard recommended in the Main Roads guidelines.
Any changes to design standards arising from environmental constraints shall be included in the 'Environmental' section (7.9).
7.3.1 Road Design Standards
The road design standards to be documented will typically consist of the following elements:
- Carriageway width(s)
- Lane width(s)
- Sealed and unsealed shoulder width(s)
- Median width(s)
- Crossfall
- Superelevation (maximum)
- Gradients (maximum and minimum)
- Design speed and expected posted speed
- Pavement depth(s)
- Intersection design vehicle(s)
- Batter slopes (cut and fill)
- Vertical clearances (between road and structures)
Where both first stage and ultimate design is requested, the road design standards should be tabulated for both.
The design standards may be presented in tabular format as shown in the example below:
Road Design Standards Adopted for the Project (Stage 1 and Ultimate)
Road B / Road A / Kwinana Freeway Link | |
Carriageway lane widths | Refer Typ. Cross-section Dwg's at Appendices A & B |
Auxiliary lane widths | 3.5m |
Shoulders - left | 2.5m wide, 1.5m sealed |
Shoulders - right (typical median) | 1.0 wide, 1.0m sealed |
Shoulders - right (next to northbound rail) | 2.5m wide, 2.5m sealed |
Median (to accommodate SWMR) | Nominally 31.0m (varies) |
Crossfall | 3% |
Superelevation | 5% maximum |
Grades | Unkerbed: 3% maximum, 0% minimum. Kerbed: 0.3% minimum |
Batters | 1 in 1.5 maximum, bridge abutments 1 in 6 typical, table drain Cut / Fill: 1 in 3 typical, interface |
Ramps (Kerbed) | |
Crossfall | 3% |
Superelevation | 6% maximum |
Grades | 6% maximum, 0.3% minimum |
Verges | 2.0m wide minimum, 2% typical |
Batters | Cut / Fill: 1 in 3 typical, interface |
Single Lane Ramp | |
Carriageway lane width | 1 lane 4.2m wide> |
Shoulder - left | 2.8m wide, 2.8m sealed |
Two Lane Ramp | |
Carriageway lane widths | 2 lanes, 3.5m wide each |
Shoulders | None |
Side Roads | |
Carriageway (dual with median) lane widths | 2 lanes each way, 3.5m wide each |
Carriageway (single) lane widths | 2 lanes, 3.5m wide each |
Shoulders (dual carriageway with median) | Outside: 2.5m wide, 1.5m sealed Median: 1.0m wide, 1.0m sealed |
Shoulders (single carriageway) | 2.5m wide, 1.0m sealed |
Crossfall | 3% |
Superelevation | 5% maximum |
Grades | 6% maximum, 0.3% minimum |
Verges | 2.0m wide minimum, 2% typical |
Batters | 1 in 3 typical |
Design Speed * / Posted Speed |
|
Road B | 80km/h / 70km/h |
Fremantle Road/Centennial Park Estate | 60km/h / 50km/h |
Meadow Springs Access Road (Cha 2500) | 50km/h / 50km/h |
Road A | 90km/h / 80km/h |
Kwinana Freeway Link | 90km/h / 80km/h |
Meadow Springs/Waste Transfer Station Access | 40km/h / 40km/h |
Gordon Road | 70km/h (low speed environment) / 60km/h |
Ramps (standard) | 70km/h / 60km/h |
Ramps (parclo) | 40km/h / 40km/h |
Exchequer Road/Fremantle Road | 70km/h / 60km/h |
Pavement Design |
|
Road B / Road A / Kwinana Freeway Link | |
Pavement Depth | 350mm |
Basecourse Layer | 100mm |
Sub-base Layer | 250mm |
Side Roads | |
Pavement Depth | 250mm |
Basecourse Layer | 100mm |
Sub-base Layer | 150mm |
Design Vehicles (Intersections) |
|
Fremantle Road/Centennial Park Estate | Semi-Trailer |
Meadow Springs Access Road (Cha 2500) | Semi-Trailer |
Kwinana Freeway Link | B-Double |
Meadow Springs/Waste Transfer Station Access | Semi-Trailer |
Gordon Road Interchange | B-Double |
Exchequer Road/Fremantle Road | B-Double |
* The proposed design speed for Road A was originally 110km/hr. (Main Roads Design Brief Section 2.12). However, this design speed could not be achieved due to the constraints of the PRS road corridor, especially at Gordon Road Interchange, and the requirement for signalised intersections.
Table 1 - Road Design Standards Adopted for the Project
Refer to 'Main Roads Supplement to Austroads Guide to Road Design – Part 3: Geometric Design' (Document No. D11#308695).
7.3.2 Drainage Design Standards
The drainage design standards to be documented will typically consist of any of the following:
- Design ARI for all specific elements of the design - e.g. spread, underground pipe design, culverts, erosion checks etc.
- Minimum velocity for piped systems and culverts.
- Maximum velocity for piped systems and culverts.
- Limiting (Scour) velocity at the outfall.
- Minimum grades for table drains.
- Environmental factors influencing the design.
- Consideration of the impacts of climate change.
Refer to 'Main Roads Supplement to Austroads Guide to Road Design - Part 5: Drainage - General and Hydrology Considerations' (Document No. D15#370385).
7.3.3 Extended Design Domain and Design Exceptions
Where Normal Design Domain standards such those listed in the Main Roads guidelines are not able to be met, the use of Extended Design Domain (EDD) or Design Exception (DE) may be warranted for existing road projects. The use of EDD or DE standards shall only be used with MRTE and EDPTS approval.
Main Roads Guidelines for the Detailed Assessment of Existing Rural Road Sections can be found here.
The approval process consists of:
- Determine the impacts of meeting NDD and evaluate any alternative solutions such as a lowered the posted speed.
- Initiate discussion with MRTE – the use of EDD or DE approved in principal
- Submit paper demonstrating the need for EDD or DE including proposed EDD base case for MRTE sign off
- Prepare EDD / DE report as per link to process above for review by MRTE
- EDPTS Approval
Proceed with design based on EDD / DE principles.
The EDD / DE Report shall be included as an appendix to the Design Report. Alternatively, the TRIM reference shall be provided. Notwithstanding this, as a minimum, all geometric elements for which EDD / DE standards have been adopted shall be highlighted in this section of the Design Report.
Extended Design Domain for Geometric Road Design is documented in Austroads Guide to Road Design – Part 3 Appendix A.
7.4. Design
This section should discuss and summarise the design considerations including any alternatives and identify any issues to be resolved. Issues to be resolved should be summarised in the "Issues to be Resolved" Section 7.13.
7.4.1. Road Design
7.4.1.1. Software
State the design software used to undertake the road design.
7.4.1.2. Cross-Section
Discuss the relationship between the typical road cross-section configurations for the first stage and ultimate designs giving particular attention to the following:
- Horizontal and vertical alignments.
- Design levels.
- Extent of earthworks and batters.
Typical cross-section drawings should be included in the 'Appendices' section of the report or referred to by drawing or sketch number. The typical cross-section drawings should be dimensioned showing all relevant offsets, particularly at structures, safety barriers or offsets to railways.
Refer to 'Main Roads Supplement to Austroads Guide to Road Design – Part 3: Geometric Design - Chapter 4' (Document No. D11#308695).
7.4.1.3. Horizontal Alignment
Discuss the design considerations with reference to the following relevant elements;
- alignment length, chainage system,
- design speed,
- curve radii range, plan transitions,
- realignment(s) in relation to the existing road,
- tie-ins,
- relationship of first stage horizontal alignment to ultimate alignment,
- alternative horizontal alignments,
- variances to Main Roads lateral clearance requirements to ensure that minimum horizontal sight distances are maintained at all times, constraints, etc.
Refer to 'Main Roads Supplement to Austroads Guide to Road Design – Part 3: Geometric Design - Chapter 7' (Document No. D11#308695).
7.4.1.4. Vertical Alignment
Discuss the design considerations with reference to the following relevant elements;
- VPI spacing, gradients,
- sight distance (especially identify those locations where the minimum sight distance has not been achieved),
- superelevation, superelevation transition lengths, superelevation VC roundings,
- clearances for grade separation,
- relationship of first stage vertical alignment to ultimate alignment,
- relationship of vertical profiles for each carriageway (in the case of dual carriageways),
- alternative vertical alignments,
- cut and fill depths,
- constraints, etc.
Refer to 'Main Roads Supplement to Austroads Guide to Road Design – Part 3: Geometric Design - Chapter 8' (Document No. D11#308695).
7.4.1.5. Tie-In Sections and Blend Areas
Discuss the design considerations where the proposed roadworks tie into existing road sections including reference to blend areas, diverge/merge tapers and the adequacy of sight distances for the tie-in sections.
7.4.1.6. Passing / Overtaking Lanes
Discuss the following design considerations for overtaking lanes (if relevant):
- Warrant for overtaking lanes.
- Length of overtaking lanes.
- Location of overtaking lanes (to maximise benefits and minimise costs).
Refer to 'Main Roads Supplement to Austroads Guide to Road Design – Part 3: Geometric Design - Chapter 9' (Document No. D11#308695).
7.4.1.7. Road Widening
Discuss the following design considerations for the road widening (if relevant):
- Warrant for the road widening.
- Length and location of the road widening.
- Methodology used for designing the road widening (e.g. widening by extension of the existing road surface or widening by specific crossfall).
- Profiling of the edge of the road widening to improve appearance and/or drainage.
7.4.1.8. Intersections, Roundabouts and Interchanges
Discuss the design considerations with reference to the following relevant elements;
- traffic assessment,
- design speed,
- horizontal and vertical alignments,
- sight distances,
- left and right turn lane treatments (free flow slip lane, 70 deg. standup),
- deceleration lane lengths,
- acceleration lane lengths,
- cyclist facilities,
- traffic islands,
- paving,
- pedestrian facilities,
- dual-use-paths,
- underpasses,
- bridges,
- ramps,
- traffic signal control,
- swept path design vehicle(s),
- ability to turn lane correct,
- clearances for grade separation,
- alternative alignments,
- cut and fill depths,
- constraints, etc.
Refer to ’Main Roads Supplement to Austroads Guide to Road Design – Part 4: Intersections and Crossings - General’ (Document No. D11#308722), ’Main Roads Supplement to Austroads Guide to Road Design – Part 4A: Unsignalised & Signalised Intersections’ (Document No. D11#308726), ’Main Roads Supplement to Austroads Guide to Road Design – Part 4B: Roundabouts’ (Document No. D11#308732) and ’Main Roads Supplement to Austroads Guide to Road Design – Part 4C: Interchanges’ (Document No. D11#308735)
7.4.1.9. Pedestrian and Cyclist Facilities
Discuss the design considerations for pedestrian and cyclist facilities with particular reference to the following relevant elements;
- the incorporation of special facilities that best meet the needs of school children,
- people with disabilities and cyclists including hazard warning treatments path gradients, and tactile ground surface indicators.
- traffic island treatments, head-start cycle lanes, grab rails and ramps,
- temporary access requirements to existing pedestrian and cyclist facilities affected by road construction works etc.
Refer to Main Roads Guideline to 'Pedestrian and Cyclist Facilities' (Document No. D11#317418).
7.4.1.10. High Wide Loads
Discuss the design considerations with reference to the following relevant element;
- the design vehicle and load, route assessment,
- road and ramp widths,
- swept path envelopes for vehicle and load,
- horizontal clearances to road furniture,
- vertical clearances to bridges and overhead power lines,
- maximum grades and superelevation or crossfall,
- vertical clearance analysis between the high wide load trailer deck and the road surface where warranted by the road geometry,
- pavement structure and surfacing criteria, etc.
Refer to Main Roads Guideline to 'Guide to Design and Operation of High Wide Loads' (Document No. D11#318284).
7.4.1.11. Bus Facilities
Discuss the requirement and treatment for new and/or relocated bus facilities with reference to the following relevant elements;
- location,
- length (including entry and exit tapers),
- drainage,
- hard standing areas,
- tactile ground surface indicators,
- bus shelters,
- traffic signs and pavement marking.
Refer to Main Roads Supplement to Austroads Guide to Road Design - Part 4: Intersections and Crossings - General' (Document No. D11#308722).
7.4.1.12. Driveways
Discuss the requirement and treatment for reinstated, relocated and new driveways.
Refer to Main Roads 'Guide to the Geometric Design of Driveways' (Document No. D12#57413).
7.4.1.13. Rest Areas (Roadside Stopping Places) and Other Roadside Features
Discuss the design considerations with reference to the following relevant elements;
- the location and spacing of parking bays and rest areas,
- facilities at parking bays and rest areas,
- truck arrestor beds etc.
Refer to Main Roads Guideline 'Policy and Guidelines for Rest Areas' (Document No. D16#249528).
7.4.2. Pavement Structure and Surfacing Design
Discuss the pavement structure and bituminous surfacing design with reference to the outcomes of the geotechnical investigations and the following relevant elements;
- design period traffic volumes and composition,
- existing and adjoining pavement,
- pavement design,
- subgrade material, proposed sub-base material, proposed basecourse material,
- proposed bituminous primerseal (emulsion coating and aggregate chip size),
- proposed bituminous chip seal or asphalt wearing coarse and
- special treatments, e.g. floodways etc.
7.4.3. Earthworks and Batter Slopes
Discuss, with reference to the outcomes of the geotechnical investigations;
- the proposed embankment fill material,
- any deviation from the design batters specified in Section 7.3.1,
- unsuitable materials,
- any special treatments proposed e.g. stone pitching, scour protection for high fill embankments etc.
- any special maintenance requirements. (This may be documented at 7.11.2).
7.4.4. Road Safety Barriers
Discuss the warrants for safety barriers for the following;
- proposed fill embankments,
- bridge abutments and piers,
- drainage features and fixed roadside furniture.
The sections warranting safety barriers should be tabulated and may be included in the 'Appendices' section of the report or the main body of the report along with the 'length of need' calculations.
Locations where the safety barrier interferes with sight distances should be clearly identified and documented.
Any special maintenance requirements should be discussed e.g. maintaining the hazard free area behind gating end treatments. (This may be documented at 7.11.2).
Refer to Main Roads 'Supplement to Austroads Guide to Road Design - Part 6: Roadside Design, Safety and Barriers' (Document No. D11#38472).
7.4.5. Drainage Design
Discuss the drainage system and in particular the following issues:
- Design philosophy.
- Failure mechanism of the system.
- Consequences of failure in the major event.
- Outlets for the drainage system e.g. outfalls to water bodies rivers, lakes etc.
- Drainage basins - retention, detention basins etc.
- Protection of drainage features - see also 7.4.4 Safety Barriers.
- Ground types.
- Any special treatments for scour, overflow paths etc.
- Floodways.
- Conformance to environmental standards and constraints.
- Consideration of the impacts of sea level rise.
- Consideration of the impacts of shifting rainfall patterns.
- Minimum maintenance requirements for sub-soil drainage. (May be documented at 7.11).
Refer to Main Roads Guidelines ’Main Roads Supplement to Austroads Guide to Road Design – Part 5: Drainage – General and Hydrology Considerations’ (Document No. D15#370385), ’Main Roads Supplement to Austroads Guide to Road Design – Part 5A: Drainage – Road Surface, Networks, Basins and Subsurface’ (Document No. D15#415254) & ’Main Roads Supplement to Austroads Guide to Road Design – Part 5B: Drainage – Open Channels, Culverts & Floodways’ (Document No. D15#363173).
7.4.6. Accommodation Works
7.4.6.1. Fencing
Discuss the requirement for fencing.
7.4.6.2. Noise Barriers and Retaining Walls
Discuss the design considerations and requirement for retaining walls to limit the extent of earthworks and barriers to attenuate traffic noise on adjoining residential land.
Refer to Main Roads Guideline 'Guide to the Design of Fencing and Walls' (Document No. D11#319186).
7.4.7. Lighting Design
Discuss the design considerations for the installation of new street lighting and/or the modification to existing street lighting.
Refer to Main Roads Guideline 'Lighting Design Guideline for Roadway and Public Space' (Document No. D17#69316).
7.4.8. Traffic Signals
Discuss the design considerations for the installation of new traffic signals and/or the modification to existing traffic signals with reference to the following relevant elements;
- vehicular signals,
- pedestrian signals,
- advance warning signals,
- red light cameras,
- ramp metering,
- mast arms,
- heavy vehicles and high wide loads,
- queuing lengths and possible upstream conflicts eg. railway crossing,
- the provision of U-turns at traffic lights,
- phasing and timing.
Refer to Main Roads Guidelines 'Traffic Management Guidelines for Traffic Signals - Vehicular Signals' (Document No. D15#792478), 'Traffic Management Guidelines for Pedestrian Signals' (Document No. D08#6040) and 'Traffic Management Guidelines for Advance Warning Traffic Signals' (Document No. D12#267009).
7.4.9. Signing and Linemarking
Discuss the design considerations for the installation of new signs and/or the modification to existing signs with reference to the following relevant elements;
- major and minor signing,
- supporting posts,
- the relocation of existing signs and the removal of redundant signs.
Discuss the design considerations for linemarking (including roadmarking) such as removal of existing linemarking and new marking.
Refer to Main Roads Standards Contract Drawings 'Pavement Marking' (Document No. D13#492336).
7.4.10. Roadside Help Phones (Emergency Telephones)
Discuss the design considerations for emergency telephones including placement behind road safety barriers, access by disabled persons and signing.
Refer to Main Roads Guideline 'Design and Installation of Roadside Help Phones' (Document No. D12#402897).
7.4.11. Road Safety Audits
The results of a road safety audit generally takes the form of a separate report.
Details of any road safety audits undertaken including the names of the auditors and dates of the audits should be included in the design report.
Any issues arising from the Road Safety Report(s) should be identified and addressed.
A copy of the closeout report for the audit should be contained as an Appendix to the design report.
Refer to Main Roads 'Policy and Guidelines for Road Safety Audit' (Document No. D15#159750)
7.4.12. Safety in Design
Designers shall consider Safety in Design guidance as shown in 201.8.2. This will demonstrate their requirements to comply with Regulation 295 of the Work Health and Safety (General) Regulations 2022, Part 6.2: Duties of designer of structure and person who commissions construction work.
7.4.13. Sustainability
Designers shall document the design's response to all six aspects underpinning Main Roads policy on Sustainability, as detailed in Section 201.9.
7.5. Services
This will identify services that may be impacted on by the project. The following relevant services within the road design corridor will be identified; Telstra (with particular reference to optic fibre cables), Western Power (with particular reference to high voltage power lines and towers), Alinta Gas, Water Corporation (stormwater and sewerage mains) , and Local Government (stormwater).
The results of the existing services investigation should be tabulated and included in the design report.
Reference should be made to the source of the services information e.g. the One Call Dial Before You Dig system.
A copy of the existing services plans and proposed relocation of services plans may be included in the 'Appendices' section of the report.
The following documentation as a minimum should be prepared to support proposed new works and relocation / protection works:
- Cost estimates for the works.
- Alternatives options for relocation of services e.g. protection of services or adjusting of road alignment or profile to avoid significant services.
- Access requirements to services if applicable.
- Timing issues e.g. certain services can only be relocated during particular time of the year due to availability of materials or equipment etc.
Any other issues which should be brought to the Project Manager's attention.
A copy of the proposed services plans and copies of correspondence (i.e. letters sent / received) may be included in the 'Appendices' section of the report.
Refer to Main Roads Guideline 'Utility Services in Road Reserves - Policy and Guidelines (Document No. 15-01-10).
7.6. Geotechnical Investigation
This will either include any necessary information on the geotechnical investigation issues or make reference to a separate geotechnical report. Reference to a standalone report shall include the name of the report, the company the report was prepared by, the date and a reference number for the report.
This may include a description of the geological units through which sections of the road alignment traverse e.g. pebbly silt, sandy silt, sandstone, limestone, granite etc. The report should also discuss the groundwater considerations.
The extent of rock is of particular interest due to the impact on the construction cost and may need to be discussed further in the 'Issues to be Resolved' section of the report.
7.7. Structures
This will either include any necessary information on the structural design issues or make reference to a separate structural design report. Reference to a standalone report shall include the name of the report, the company the report was prepared by, the date and a reference number for the report.
7.8. Landscape Design
This will either include any necessary information on the landscape design issues or make reference to a separate landscape design report. Reference to a standalone report shall include the name of the report, the company the report was prepared by, the date and a reference number for the report.
This should include advice on the conformance of the landscaping design to the landscape strategy for the area.
7.9. Environmental
This will either include any necessary information on the environmental issues and any changes to design standards arising from these issues or make reference to a separate environmental report. Reference to a standalone report shall include the name of the report, the company the report was prepared by, the date and a reference number for the report.
This may include a comprehensive environmental assessment of heritage sites, flora and fauna, social issues, noise and hydrology including an environmental management plan.
7.10. Land Requirements
This will discuss and identify where additional land is required for road or other purposes with particular reference to 'A' class reserves, and other land which may require long lead times to acquire, and the estimated period to resume or acquire the land.
Copies of all correspondence with land holders shall be included in the 'Appendices' section of the report. Note any commitments.
7.11. Construction, Maintenance and Traffic Management
7.11.1. General
This will discuss the following relevant details;
- the existing road layout and traffic movements,
- the proposed changes to the road layout and future traffic patterns,
- construction materials required,
- the extent of 'throw away' pavement,
- specific work safety and health issues or considerations during construction,
- specific (non standard) construction requirements related to the design,
- sub-soil drainage cleaning or flushing,
- and a general overview of the construction staging, construction and traffic management.
7.11.2. Special Construction and Maintenance Requirements
This section should provide a summary of any construction and maintenance considerations brought about by some of the design choices.
Under the "Work Health and Safety Act 2020" the Designer has a responsibility to prepare the design such that as much as practicable that persons who maintain or construct the works are not in doing so, exposed to hazards. Consequently, any areas of the design requiring special consideration during either construction or maintenance activities should be highlighted in this section of the report.
For example, a retaining wall with a drain in front of it has been designed to be constructed midway down a 2 in 1 embankment. Special features such as bolts for safety lines may be required on the retaining walls to allow workers to attach a safety line to facilitate the maintenance of the drainage installed in front of the walls.
Extracts from the "Work Health and Safety Act 2020" are included in Appendix A.
7.12. Cost Estimate
This will provide a statement of the design assumptions which have been made in the preparation of the cost estimate, the basis for the estimate (e.g. rates used were based on a similar project in same region), the expected accuracy (e.g. +/- 10%), a summary of costs for the main items and a bill of quantities which gives a more detailed breakdown of the cost estimate for the construction of the proposed road project. The estimate may include the following costs:
- Project Management
- Design (where a further design phase is required e.g. detailed design)
- Construction
- General Items
- Clearing
- Earthworks
- Drainage
- Pavement/Surfacing
- Traffic Facilities
- Electrical/Lighting
- Structures
- Services
- Miscellaneous
- Dayworks
- Provisional Sums
- Contingencies
- Supervision
7.13. Issues to be Resolved
The purpose of this section is to alert the Project Manager to issues that will require resolving prior to proceeding to the next phase of the design or construction. The responsibility for the action to be taken to address these issues rests with the Project Manager.
7.14. Recommendations
This will include recommendations for further design work to be undertaken or changes in design standards to be approved by the Project Manager
7.15. Conclusion
This will summarise the aims of the design and the benefits that have been achieved resulting from the design.
8. Appendices
This will contain relevant information considered necessary to be included within the report but too bulky to be contained within the body of the text.
The information included as an appendix should be referenced in the body of the text.
Typically the following information may be included as an appendix:
- Typical Road Cross-Section Drawings (properly dimensioned)
- Road Design Plan and Profile Drawings
- Construction Staging Plans
- Existing Drainage System Plans
- Proposed Drainage System Plans
- Drainage System Catchment Plans and Calculations
- Traffic Analysis
- Letters from Service Providers and Other Stakeholders
- Figures and Sketches
- Tables
- Calculations (including drainage)
- Correspondence with land holders
Appendix A
Extracts from the "Work Health and Safety Act 2020":- Duties of manufacturers, etc.
Section 23.
- A person who designs, manufactures, imports or supplies any plant for use at a workplace shall, so far as is practicable
- ensure that the design and construction of the plant is such that persons who properly install, maintain or use the plant are not in doing so, exposed to hazards;
- test and examine, or arrange for the testing and examination of, the plant so as to ensure that its design and construction are as mentioned. in paragraph (a); and
- ensure that adequate information in respect of
- any dangers associated with the plant;
- the specifications of the plant and the data obtained on the testing of the plant as mentioned in paragraph (b);
- the conditions necessary to ensure that persons properly using the plant are not, in so doing, exposed to hazards; and
- the proper maintenance of the plant,
is provided when the plant is supplied and thereafter whenever requested. - A person who erects or installs any plant for use at a workplace shall, so far as is practicable, ensure that it is so erected or installed that persons who properly use the plant are not subjected to any hazard that arises from, or is increased by, the way in which the plant is erected or installed.
- A person who manufactures, imports or supplies any substance for use at a workplace shall, so far as is practicable, ensure that adequate toxicological data in respect of the substance and such other data as is relevant to the safe use, handling, processing, storage, transportation and disposal of the substance is provided
- when the substance is supplied; and
- thereafter whenever requested.
- A person who designs or constructs any building or structure, including a temporary structure, for use at a workplace shall, so far as is practicable ensure that the design and construction of the building or structure is such that
- persons who properly construct, maintain, repair or service the building or structure; and
- persons who properly use the building or structure, are not, in doing so, exposed to hazards.
- A person who contravenes subsection (1), (2), (3) or (3a) commits an offence and is liable to a fine of $100 000.
- A person who contravenes subsection (1), (2), (3) or (3a) and by that contravention causes the death of, or serious harm to, any person commits an offence and is liable to a fine of $200000.
- A person charged with an offence against subsection (5)
may, instead of being convicted of that offence, be convicted of an offence against subsection (4).
Definitions
"hazard", in relation to a person, means anything that may result in
- injury to the person; or
- harm to the health of the person;
"plant" includes any machinery, equipment, appliance, implement, or tool and any component or fitting thereof or accessory thereto;
"practicable" means reasonably practicable having regard, where the context permits, to
- the severity of any potential injury or harm to health that may be involved, and the degree of risk of it occurring;
- the state of knowledge about
- the injury or harm to health referred to in paragraph (a);
- the risk of that injury or harm to health occurring; and
- means of removing or mitigating the risk or mitigating the potential injury or harm to health; and
- the availability, suitability, and cost of the means referred to in paragraph (b) (iii);