3Preparation of a Traffic Management Plan#
3.3Risk assessment#
3.3.4Identify treatment options#
Add the following dot point to the treatment options to be considered:
- Mobile works – some work types and locations may be suited to implementation by a mobile works convoy. The controls applied and work arrangements for mobile work methods are set in QGTTM Part 4.
In the subsection 'Length of single-lane operation under reversible traffic flow', add the following:
Generally, when using Table 3.5, and where the lengths are within the maximum limits, single-lane operation using active control by portable traffic control devices or traffic controllers will lead to a relatively short and consistent or stable queue length; however, additional traffic engineering input and consideration (risk assessments) are required to support longer lengths of single-lane operation which will generally lead to longer maximum queue lengths and queue lengths that are not easily managed, or are variable and unstable. Contingency planning for longer than expected or continually growing queue lengths shall be included as part of the TGS design. End-of-queue protection measures (refer to QGTTM Part 3 Section 4.8.3) shall be considered.
Replace the following:
Traffic control may not be required if:
- there is clear visibility past the work area and beyond it for at least 75 m, or to the end of the road if less than 75 m away and the length of the shuttle lane does not exceed 60 m
- road users have clear visibility of the work area and the opposing approach for a distance greater than 150 m and either one of the following:
- traffic volume in both directions is 40 vph or less, and the speed is 70 km/h or less, and the length of the single lane is 60 m or less
- the length of the single lane is 100 m or less, and GIVE WAY and ONE LANE signs are provided at one end of the shuttle lane
- it is a residential street and the length of the shuttle is 60 m or less.
with
Active traffic control (by traffic controllers or PTCDs) may not be required where:
- GIVE WAY and ONE LANE signs are provided at one end of the shuttle lane and the NO OVERTAKING OR PASSING sign is also to be erected at the start of the single lane for traffic in the opposite direction and all the following apply:
- traffic volume in both directions is 150 vph or less
- the traffic speed is 70 km/h or less
- each entry to the work area is visible from the other
- the length of the single lane or shuttle flow segment is 120 m or less, and
- there is sight distance to opposing traffic of at least 200 m beyond the far end of the work area for traffic facing the GIVE WAY, ONE LANE assembly.
- No specific traffic control signs are required for the single lane section, and traffic operates under natural give and take using the one open lane and either one of the following applies:
- it is a residential street (permanent posted speed is 50 km/h or less) and there is clear visibility past the work area and beyond it for at least 75 m, or to the end of the road if less than 75 m away and the length of the shuttle lane does not exceed 60 m, or
- road users have clear visibility of the work area and the opposing approach for a distance greater than 150 m or to the end of the road if less than 150 m away, the traffic volume in both directions is 40 vph or less, the permanent posted speed is 70 km/h or less, and the length of the shuttle lane is 60 m or less.
Where active traffic control is not provided (working under natural give and take, or where GIVE WAY and ONE LANE signs are in operation), the taper should be at 45 degrees on both the approach and departure sides of the work area and the remaining open single lane section should have a maximum width of 3.5 m. See QGTTM Part 3 Figure 5.4.4(a) for an example layout.
In the subsection 'Other traffic assessment elements – Lane widths'
Replace Table 3.6 with the following:
| Criteria | Lane width (m) |
|---|---|
| General lane widths | |
| ≤60 km/h | Minimum 3.0* |
| 70, 80 or 90 km/h | Minimum 3.2* |
| ≥100 km/h | Minimum 3.4* |
| Curve with radius 100–250 m | Add curve widening of 0.5 m per lane |
| Curve with radius <100 m | In addition to the curve widening of 0.5 m per lane, consider the swept path of long vehicles (for example, buses, trams) |
| Two-way residential street | Minimum of 5.5 (sum both ways) |
| Shuttle flow operation | |
| Shuttle flow with active control (by traffic controllers or PTCDs) | Minimum 3.0* |
| Shuttle flow, without active control on residential streets, includes no control or the use of GIVE WAY and ONE WAY signs (see Section 5.4.4). | Minimum 3.0* and Maximum 3.5 to ensure vehicles take turns using a single lane |
Table in words
- For general lane widths, the lane width is minimum 3.0* for ≤60 km/h.
- For general lane widths, the lane width is minimum 3.2* for 70, 80 or 90 km/h.
- For general lane widths, the lane width is minimum 3.4* for ≥100 km/h.
- For a curve with radius 100–250 m, add curve widening of 0.5 m per lane.
- For a curve with radius <100 m, in addition to the curve widening of 0.5 m per lane, consider the swept path of long vehicles (for example, buses, trams).
- For a two-way residential street, the lane width is a minimum of 5.5 (sum both ways).
- For shuttle flow operation, the lane width is minimum 3.0* for shuttle flow with active control (by traffic controllers or PTCDs).
- For shuttle flow operation, the lane width is minimum 3.0* and maximum 3.5 to ensure vehicles take turns using a single lane for shuttle flow, without active control on residential streets, includes no control or the use of GIVE WAY and ONE WAY signs (see Section 5.4.4).
* Temporary minimum lane widths are not to be greater than existing lane widths. This minimum temporary lane width does not apply to curves of radius 250 m or less, or locations where there are fixed vertical obstructions such as fences or safety barriers within 30 cm of the edge of the lane on one or both sides. Where these conditions apply, consider widths wider than those listed previously to accommodate large vehicles. The speed to be used when considering lane width requirements is the speed limit (permanent or reduced) which is applicable to that length of road.
When selecting lane widths, especially when travel paths are confined on each side by physical barriers and / or hazards (for example excavations or safety barriers) for a significant distance, it is important to consider any impact of breakdowns and congestion for emergency vehicle access and on traffic flow. This is generally only applicable for major link roads, arterial roads or highways where maintaining traffic flow and emergency vehicle access is critical.
The following considerations may impact the selection of lane widths:
- how will traffic get past a broken-down vehicle
- how will emergency vehicles get past a broken-down vehicle or through a congested road environment
- the length of the constraint may dictate the mitigations required, as short, localised constraints may not be a large issue under normal conditions
- where possible the minimum distance between physical constraints on each side of the carriageway should allow vehicles to move off to the side to allow emergency vehicles to pass
- in addition to minimum widths between physical constraints, other mitigations may be implemented including:
- the availability of response vehicles to remove broken down vehicles to maintain traffic flow
- alternative routes or detours may also be an option, especially for emergency vehicles.
Emergency services must be advised in advance of any constrained road environment likely to impact their response times and route choice.
Currently no mention of using electronic signatures, just that the TMP and TGSs need to be signed. Added an option for signing the TMP and TGS(s) electronically.
3.4Plan and Design#
3.4.1Plan and design selected risk treatment#
A signature on the TMP or TGS(s) may be electronic.
