Special Engineering Difficulties (SED)

Note

This page details forms and layers available in the new PMS UI from version 4.6 onwards.

Overview

The SEDs module is used to create polygons representing a Special Engineering Difficulty. Any roads that fall within this polygon are marked as having the SED.

The SED module in PMS consists of the following forms:

• SEDs Grid

• SEDs Form

The following map layers are available (through the UI and also by WFS/WMS):

• SED’s Layers and Grids - this layer shows the areas of road covered by each SED

SED Values

• Bridges

• Cellars

• Culverts

• Embankments

• Excavation

• Heavy Duty Locations

• Piers

• Pylons/Poles (e.g. HT Electricity, Lights, Cameras, Transmitter)

• Quay Walls

• Railway Crossings

• Retaining Walls

• Signalised Junctions

• Special Surface Material

• Structure

Background

Note SEDs also include Heavy Duty Locations.

These are locations where specific conditions and/or restrictions may apply due to the nature of the area vehicles that use it. For example, HGVs close to a port.

Data Import

The base data for SED Zones is a subset of the OSI PRIME2 STRUCTURE POLYGONS dataset, with rows of specified FROM_VALUEs OR FUNC_VALUEs imported (see Table 1 below).

For each feature we:

1. Assign a Local Authority Id

2. Apply a spatial buffer of 10 meters

3. Create a Web Mercator projection

The buffered polygon were used to create SED Edges by cutting intersecting line features from the underlying Network Edges layer.

The resulting layers can be seen in the image here:

Buffered Zones (red) with intersecting edge (black).

Table 1 - OSI features included in import

FORM_VALUE	FUNC_VALUE
Bridge Draw	Pedestrian Bridge
Bridge Fixed	Pedestrian Bridge
Bridge Draw	Multiple Use
Bridge Fixed	Aqueduct
Bridge Fixed	Multiple Use
Bridge Fixed	Railway Bridge
Bridge Foot	Pedestrian Bridge
Weighbridge	Not Applicable
Bridge Fixed	Viaduct
Jetty	Not Applicable