Carriageway width is the average seal edge to seal edge distance along the length of the carriageway section. For carriageway sections where width varies significantly along the length, an average width determined from measurements taken at 100m intervals will suffice.
A general rule would be that where there is a significant carriageway width change, there should be a change in sectioning, eg 3m width and >150m in length. This could include slow vehicle bays and some intersection widening.
A carriageway that is well segmented should not require significant carriageway area modifications, as indicated in the diagram on the right below.
The following diagrams compare:
With regard to the diagram on the left, when the length of dual carriageway is >150m, it is treated as an increasing and decreasing road and the central median island is not considered as a negative extra area.
Note that the diagram on the left also shows how extra is treated, particularly traffic islands.
Figure 1: Regular carriageway width with extra area compared with irregular carriageway width with no extra area
The most common form of pavement type changed on state highways is from Pavement Type 'T' to Pavement Type 'B' (Bridge Deck). Typically, only bridges that are greater than 50m in length are separated out into carriageway sections.
It is important to choose easily definable and safe points as carriageway nodes and locate these nodes using accurately calibrated measuring equipment. Carriageway nodes need to fit reference stations (RS) whose lengths have been pre-determined by taking the average of three passes of the RS. Easily definable carriageway nodes include:
Figure 2: Suitable carriageway nodes
Roundabouts (>150m) are now separated out as separate roads. Refer to the LRMS manual Opens in a new window, which illustrates how these affect the carriageway table.
Where there was originally one carriageway node at a roundabout there are now two nodes (one as you enter and one as you exit) AND a separate road section (which represents the actual roundabout) and is assigned another Road ID.
The best place to stop and start roundabouts is the end and start of the roundabout approach islands respectively. This ensures that the roundabout section can be relocated even if the ERP signage is removed or the yellow square is sealed over.
Figure 3: Roundabout on state highway section > 150m
These intersections are recorded in the Features Table using Feature Type 'INT'.
Do not delete the surface records from the database.
The Removed Date is a flag that differentiates between surfaces that are currently on the network from those that have been removed as part of pavement renewal activity or milling during resurfacing. This does not apply to partial key-in milling (at start/end and edges), but it does apply to full lane or road width milling.
Removed Date must be populated for surfaces that are physically removed from the Network or become part of the pavement structure during pavement renewal activity.
Be aware that most removed surfaces do not coincide exactly with the area of pavement renewal, so you may have to get your database manager to split historical records into two or more records and apply removed date only to that part of the surface which has been removed due to pavement renewal activity. This also applies to the extent of milled areas that do not coincide with the extent of the existing surface layers (length and width).
Figure 4: Cross-sections of pavement and top surface before and after pavement renewal
When milling of existing surfaces occurs, the number of existing surface layers that require the removed date to be populated is dependent on the depth that was milled. The surface records will be removed in date order (newest to oldest), until the depth is achieved. For example, if 30mm of existing surface layers have been milled prior to resurfacing and RAMM has an existing top surface of 25mm depth (layer 1), followed by another 30mm layer (layer 2), only layer 1 is flagged as removed. Even though the milling record indicates 5mm of layer 2 has been removed, splitting the record to remove 5mm is not practical or sensible. The record for this layer (layer 2) is not updated.
Where the remaining depth of the existing surface layer is less than 15mm, due to the milling treatment depth, the surface record will have the removed date populated.
Figure 5: Cross-sections of surface structure before and after milling prior to resurfacing
Surface width is the average of several measurements from LH edge of seal to RH edge of seal. Surfaces that span one or more intersection can have a greater nominal width than the surrounding carriageway sections as intersections are typically wider.
Note that if a surfacing width varies by more than 1.5m over a length greater than 100m, then a separate surfacing record should be created for that length.
Figure 6: Surface width definition for varying width seals
|Details||Surface record||RPs||Surface width|
|Example site 1||1||0-300||7.53m|
|Example site 2||2A||0-75||7.2m|
Note that in example 2, the surface width has varied greater than 1.5m over 100m in length, therefore 3 records are required to be captured.
Follow the procedure detailed above. Surface width is the average surface width only, regardless of smaller shape changes. These are captured as part of the extra area and total sealed area details.
The field sealed_area is the correct place to store the sum of the detailed areas.
The offset of a surfacing is simply the distance from the left hand edge of the carriageway to the left hand edge of the surfacing. The offset, combined with the seal width, is used to define the location of the surface on the carriageway and indicate what portion of the carriageway has been covered, as shown below.
Figure 7: Offset and seal width indicate location of surfacing
The offset of the existing surface records may need to be updated when there has been some sort of widening activity. For example, if you construct a new 3.5m wide left hand (increasing direction) passing lane on an existing 7m wide road, then the passing lane surfacing will have:
And the existing surfacing that runs concurrently with the passing lane will have a revised:
Do not use negative offsets to indicate the widening, but ensure that all underlying surfaces are manipulated to match the new offsets resulting from the construction of the passing lane.
If a new 3.5m wide right hand (decreasing direction) passing lane is to be constructed on the right hand side of a 7m wide road then the passing lane will have:
All of the other surfacing records will remain unchanged, see diagram below.
Figure 8: Offset seals for LHS and RHS seal widening
This is the expected life (in years) of the surface at the time of design and is site specific. It is determined by the surfacing designer (it is not the default life). This should not be changed during the life of surface.
This is the original NZ Transport Agency Default Life (in years) at the time of entry of the surfacing record. This will never be updated.
Modified default life
If the NZ Transport Agency updates the default life in the surface life table then the modified default life for any surfacing records will be updated by the asset management software. You cannot update this value.
Refer to the examples included in the chip seal types and surface types questions below for specific details on data requirements for these types of treatments. Ensure the notes field of the surface record provides details on the method used for the treatment applied.
A sandwich seal is used to absorb excess binder on a flushed seal. It is a two layer chipseal where the 1st sealing chip is applied to the existing surface without a binder, then followed by a binder coat and a second coat of a smaller sealing chip. It is used to treat existing flushed pavement surfacing.
A combination chipseal uses a sandwich seal in the wheel paths and a voidfill seal outside the wheel paths in the un-trafficked areas.
Another option for combination seal is a two coat seal applied full width as the second layer, or when various chip aggregate grades are applied in a single application.
Combination seals are used in areas of flushing and/or rutting in the wheel paths as a result of heavy traffic loading.
Refer to the chip seal types examples included in the inventory collection table [PDF, 107 KB].
Refer to the mix types examples included in the inventory collection table [PDF, 133 KB].
An overlay is simply new pavement material placed over the top of an existing road surface. In this situation, the pavement layer data can be simply added to the database.
If the surfacing has not been removed, the surface_removed date should be populated because the surface is now part of the pavement and not part of the surface. There should also be a new layer added to the pavement layer table indicating the length of composite material, representing the surfacing layers that now form part of the pavement. Any scarification of the existing seal layer should be recorded in the notes of the new pavement record.
When a rip and remake is undertaken the pavement and surfacing layers are to be updated. For the newly created pavement layer; a new record must be added. The existing pavement record(s) must also be updated to reflect the change in depth resulting from the removal of part of the pavement. For the surfacing layer, a new record must also be added.
Figure 9: Example of a Rip and Remake
The following fields must be populated if you have stabilised an existing pavement:
Using the Pavement Builder in RAMM will do this automatically.
Pavement Data is treated the same as Surfacings Data where widening is concerned. Refer to section 3 of the State highway database operations manual for further details. If the pavement is widened on the left-hand side but the widening does not run the full length of the existing pavement record, then the record for that pavement must be split. Do not add a record if the added pavement width is less than 2m and the length is less than 100m.
Recycled material is existing pavement material (from onsite or offsite) used to rehabilitate the pavement layers. This may include a modifying agent to increase structural capacity or correct functional properties (rut, roughness, skid resistance, etc). During the process additional newly imported 'make up' material can be added prior to stabilisation to address shape correction issues or increase structural capacity (pavement thickness). If any elements of the layer are made up of recycled material, enter True; if all material used is new material, enter False.
Structural asphaltic concrete is an asphaltic concrete layer greater than 80mm thick that provides structural support and is not a surfacing layer (SMA or OGPA).
Typically most pavements are comprised of more than one layer, eg prepared subgrade, sub-base and basecourse. The subgrade is on the bottom, the sub-base is on top of the subgrade and the basecourse is between the sub-base and the 1st Coat Seal. RAMM determines the order of Layers by their dates, so the older a layer, the lower the layer sits relative to surrounding layers. The youngest layer sits on top. Even if you place both basecourse and sub-base on the same day, you must nominate the basecourse to be the top layer by assigning it a younger date in relation to the sub-base (one day younger will suffice).
Figure 10: Pavement with multiple layers
Any pavement renewal shorter than 50m should be loaded as a pavement repair in the Maintenance Cost Table and not loaded into the Pavement Layer Table, unless the road section is a ramp or roundabout and is less than 50m.
New pavement layer data must be 'integrated' into existing pavement layer records. This is mandatory when you have stabilised an existing layer, or are undertaking left-hand side widening (refer to offset pavement layers described above).
If the pavement material has been removed during Pavement Construction then it will need to be tagged as 'removed' in the Database. This is done by populating the 'removed_date' field.
In this situation, you will need to add an estimated layer to the Pavement Layer Table, which you can then add the stabilised details. Set the 'Estimated/Known' field to E to show that the record is estimated; use '25/12/xxxx' as the pavement layer date where XXXX is the estimated year that the original layer was laid.
Example 1: AWPT with Stabilisation from RP0 to RP1000
You have ripped up and removed the existing surface, adding 100mm of new Pavement Material (GAP40) and stabilised to a depth of 200mm using Cement at 2%. There is no existing Pavement Layer data in RAMM. Your Pavement Layer Table was originally blank, but will look like:
|Start m||End m||Date||Rem-oved date||Estim-ated / known||Material||Depth||Modified||Modified %||Modif-ying agent||Notes|
|0||1000||17/02/ 2005||K||Comp-osite||200||Y||2||Cement||100mm GAP40 make-up material added|
|0||1000||25/12/ 1980||17/02/ 2005||E||UNK||100||N||2||Cement|
Note: You will also have to remove the surfacing(s) that runs concurrently with the Area Wide Pavement Treatment.
Example 2: Left-Hand Side Seal Widening from RP300 to RP600
You are seal widening from RP300 to RP600 at an average width of 3.5m using 150mm of GAP65 and 100mm of GAP40. There is currently a pavement layer record from RP0 to RP1000 as shown in the following table:
|Start m||End m||Date||Estimated / known||Material||Depth||Modified||Modification %||Width||Offset|
Once you have added the widening layer to RAMM your layer data should now look like this:
|Start m||End m||Date||Estimated / known||Material||Depth||Modified||Modification %||Width||Offset|
Note that there are now 8 rows of data where there were originally 2. As you will also be sealing the widening, the same propagation of data must take place in the Surfacings Table.
For further information contact HNOperformance@nzta.govt.nz.