The Architect’s Guide to Integrated Traffic Coordination
Coordinating with a traffic consultant is a high-stakes balancing act. Misalignment between the traffic report and the architectural set can lead to non-compliant car parking arrangements, structural clashes, or vehicles getting stuck on ramps.
This checklist serves as a coordination bridge, ensuring that the data in the traffic report is accurately translated onto your plans and sections.
1. WHEN ARE TRAFFIC CONSULTANTS ENGAGED & FOR WHICH BUILDING CLASSES?
Timing: Engaged during the DA phase for parking and servicing approvals; during Detailed Design only if complex layouts or council conditions require further traffic input.
Classes: Primarily engaged in building classes 2–9 as they have complex access or servicing requirements.
2. WHAT INFORMATION DO THEY PROVIDE, AND HOW DO YOU COORDINATE IT?
A. Parking Quantities & Allocation
Information from Consultant: Parking requirements for bicycles, cars, and accessible parks for both visitors and occupants.
Architectural Check: Cross-reference the car parking provision on the GA plans against the traffic engineer’s report. Confirm the "Visitor" split is correct; these are often required to be in a more accessible location (e.g., outside a security gate).
Show on Plans: Number each bay; label "Visitor" & "Resident” parking clearly.
AS Citation: The number of bicycle and car parking spaces is determined by the local government area in which the proposed project is located. Check with the planner or traffic engineer if unsure.
B. Parking Design
Information from Consultant: Car and bicycle parking design parameters, including car parking width, car parking length and aisle width.
Architectural Check: Review the user class requirement to influence the car parking layout. Cross-reference the car park design shown on the GA plans against the traffic engineer’s design review. Confirm that any amendments required are correct and maintain the car parking provision requirements.
Show on Plans: Annotate the dimensions of a standard bay width, length and aisle width.
AS Citation: The dimensions for the car parking layout can be found in AS2890.1 (Cars). The size of the bicycle, car, and accessible parks comes from AS 2890.1 (Cars), AS/NZS 2890.6 (Accessible) and AS 2890.3 (Bicycles). If you are unable to find this, check with the traffic consultant to ensure you are selecting the correct parking bay size.
C. Commercial Vehicle Loading & Parking
Information from Consultant: The designated vehicle classes required for the site (e.g., SRV, MRV or HRV), their specific loading bay dimensions, and the required vertical clearance.
Architectural Drawing Check: Verify that the "Vertical Clearance" is maintained throughout the entire travel path, from the street entry to the loading bay, not just at the bay itself. Ensure that the footprint of the loading area accounts for both the vehicle size and the additional space required for loading/unloading activities.
Show on Plans: Delineate the loading area with a clear boundary line marking; overlay the "Swept Path" diagrams to prove the vehicle can enter and exit the bay in the required number of manoeuvres. Label the bay with its specific vehicle size (e.g., "MRV Loading Bay").
AS Citation: The size of the loading area and clear head height requirements for off-street commercial parking come from AS 2890.2. Because bay dimensions vary significantly based on vehicle class and site-specific characteristics, always cross-check with the traffic consultant to ensure you are selecting the correct size.
D. Vertical Clearance Requirements
Information from Consultant: Minimum vertical clearances for cars, accessible bays, and commercial vehicles.
Architectural Check: Measure from the Finished Floor Level (FFL) to the lowest obstruction, usually fire sprinklers, cable trays, mechanical ducts or structural beams. Note that accessible bays require 2.5m clearance above the bay and the shared zone, and the pathway to the bay needs to be a minimum of 2.3m. Verify the clear height for the entire travel path, not just the park itself.
Show on Plans: Indicate "Minimum Clear Height" at the entry and throughout sections. Check the clear head height against your RCPs.
AS Citation: The vertical clearance requirements come from AS 2890.1 (for Off-street car parking), AS 2890.2 (for commercial vehicles) and AS/NZS 2890.6 (for accessible carparks).
E. Sight Triangle Dimensions
Information from Consultant: Visibility zones are required at the property boundary for pedestrian and vehicle safety.
Architectural Check: Ensure no walls, columns, or landscaping over 600mm tall sit within these triangles.
Show on Plans: Show standard pedestrian sight triangles measuring 2.0m (width along boundary) x 2.5m (depth into site) on both sides of all exit driveways/points. Coordinate with the Traffic Consultant's report to ensure exact alignment with the property boundary and site entry levels.
F. Off-street Car Parking Geometry & Aisle Specifications
Information from Consultant: Bay widths, lengths, and aisle widths based on the "User Class."
Architectural Check: Measure the "clear" width between columns. If a bay is adjacent to a wall, it usually requires an extra 300mm "shy distance" to allow the car door to be opened. Overlay the AS 2890.1 parking template onto every bay adjacent to a structural element. You must ensure that columns are positioned so they do not encroach into the door opening zone. If a column falls within this zone, you must either relocate the column or widen the bay by 300mm to maintain compliance.
Show on Plans: Explicitly dimension the clear width between column faces and the aisle width. Note any bays that have been widened to account for the door-swing obstructions.
AS Citation: The size of off-street car parks and aisle widths comes from AS 2890.1, and for accessible parks, it comes from AS/NZS 2890.6. If you are unable to find this, check with the traffic consultant to ensure you are selecting the correct parking bay size.
G. Ramp Gradients & Transitions
Information from Consultant: Maximum gradient and required transition gradients.
Architectural Check: Ensure the 2.0m transition segments are included in your overall ramp length to prevent vehicle "grounding" if the ramp is steeper than a 1:8 gradient. Non-compliant grades can be supported by a traffic engineer through a ground clearance assessment. Provide the traffic engineer with the non-compliant grades and request that a ground clearance assessment be completed and have them amend the grades where necessary.
Show on Plans: Show ramp gradients direction and FFLs at every break-point. Also show the dimensions of the ramp and the transitions in the ramp.
AS Citation: AS 2890.1 (Section 2.5). If you are unable to find this information, check with the traffic consultant.
H. Shared Zones for Accessible Parking
Architectural Check: Ensure no structural columns or obstructions are located within the shared zone. It must be perfectly level with the parking bay.
Show on Plans: Diagonal hatching and a dedicated bollard as shown in AS 2890.6.
AS Citation: The requirements for accessible parking come from AS/NZS 2890.6.
Manoeuvring: Shared zones can be used for vehicle movements, provided there is no encroachment on the bollard. Have the traffic engineer run a swept path assessment if unsure.
I. Blind Aisle Extensions
Information from Consultant: Requirement for a turnaround area at the end of dead-end aisles.
Architectural Check: If an aisle doesn't loop, you typically need a 1.0m extension beyond the last bay to allow for manoeuvring.
Show on Plans: Dimension the extension "nub" at the end of the aisle.
AS Citation: AS 2890.1 (Clause 2.4.2).
J. Swept Path Assessment
Information from Consultant: Turning templates for the largest vehicles expected on site.
Architectural Check: Verify that the vehicle "envelope" doesn't hit the column, the walls or overhead services. Check that the driveway is wide enough to accommodate the largest service vehicle.
Show on Plans: Overlay the consultant’s swept paths on the RCPs and GA Plans to ensure that there are no clashes.
3. Common Coordination Pitfalls:
Overlooking Column location: A standard 2.4m bay works until you put a column next to it. If the column is in the "door opening zone," the bay must be wider, or the column must be moved away from the door opening zone. Always check the car park template from AS 2890.1 against the column layout.
Falls on Accessible Parking Bays: AS/NZS 2890.6 has strict requirements for gradients within accessible parking bays and shared areas. Falls must not exceed 1:40 in any direction. Non-compliant gradients can be difficult and costly to rectify during construction, making early coordination and set-out critical.
Accessible Parking vs. Pathway: Distinguish between the parking requirements (AS/NZS 2890.6) and the accessible path of travel (AS 1428.1). While the bay is capped at 1:40, the pathway to the entry may transition to a ramp with a gradient up to 1:14, provided it includes landings and handrails. Failing to coordinate the level transition between these two zones is a frequent source of design friction.
Services Creep: If the traffic report mandates a 2.3m clear height, the architectural coordination must ensure that the absolute lowest point of any overhead element, including structural beams, mechanical ducts, hydraulic pipes, and fire sprinklers, maintains a minimum of 2.3m vertical clearance from the finished floor level throughout the entire path of travel.
90 Degree Bends: Councils are becoming stricter on the provision of 90 Degree bends and the ability for a B99 to pass a B85. Where required, widening is required further to the minimum aisle width.
Overlooking the Grounding Transition: Forgetting the 2.0m transition at the top/bottom of a 1:4 or 1:5 ramp. Without this, low-clearance vehicles will scrape their bottoms.
Overlooking Existing Site Services: Existing site conditions must be carefully reviewed to identify any potential conflicts with existing services and infrastructure. Common issues include clashes between proposed driveway locations and existing power poles, Telstra pits, or other utility assets. Relocating these services can result in significant additional costs and project delays, making early identification and coordination essential.