Oversize Loads And Route Assessment

A module is a building travelling on a public road, and the road decides how big it can be.

Which means the transport route is a design input rather than a logistics task, and it is assessed before the dimensions are locked.

What the assessment looks at

Every constraint between the factory gate and the site, in order.

**Vertical clearances.** Bridges, overpasses, tunnels, awnings, overhanging trees and overhead power and communication lines. The lowest point on the route sets the maximum height of the load including the trailer deck.

**Horizontal clearances.** Road widths, lane widths, median islands, kerb build-outs, parked vehicles. The narrowest point sets the maximum width.

**Turn geometry.** Intersections, roundabouts and the final turn into the site. A long rigid load has a sweep path that needs far more space than the road carriageway suggests, and the last turn into a suburban street is frequently the governing constraint on the whole route.

**Weight and bridge capacity,** including load limits on local bridges and culverts that do not appear on a map.

**Street furniture and signage,** which can be temporarily removed with authority approval and which has to be identified first.

**Grades,** because a steep approach limits what can be hauled and changes the vehicle configuration.

The constraint feeds back into the design

The output of the assessment is a maximum height, width, length and weight per module.

That then decides how the building is divided. A dwelling that would ideally be two wide modules may have to be three narrower ones because of a single turn, and that changes the internal layout, because each module join is a wall line with a structural and acoustic detail at it.

Which is why the question of how a building breaks into modules is answered after the route is known, not before. The relationship between dimensions and dwelling layout is in [how many modules make a dwelling](/blog/how-many-modules-make-a-dwelling).

It is also why changing a site late in a project is consequential. A design optimised for one route may not travel to another.

Permits, escorts and conditions

Once the dimensions are set, the load falls into a permit class.

**Within standard limits,** travelling as a normal heavy vehicle with no special permission.

**Oversize, requiring a permit,** with conditions on route, timing, signage and warning lights.

**Oversize requiring pilot or escort vehicles,** one or more, with the number increasing with width.

**Oversize requiring police escort and traffic management,** at the upper end, with road closures and a narrow time window.

Each step up adds cost and reduces flexibility. A load that requires a police escort can usually only move at specific hours on specific days, which means the installation date is set by the escort availability rather than by the project.

And the permits take time. They are applied for well in advance, and a late design change that pushes a module into a higher class can cost weeks.

Timing

Most oversize movements happen at night or in off-peak hours, which affects the whole installation sequence.

A module arriving at four in the morning has to be received, which means site access, lighting, a crew and somewhere to stand the trailer until the crane is ready. That staging is part of [site establishment before modules arrive](/blog/site-establishment-before-modules-arrive).

On a multi-module project the arrival sequence is planned so modules arrive in installation order, because there is rarely room to store them. The logic is the same as [staging deliveries across a large project](/blog/staging-deliveries-across-a-large-project).

Regional and remote routes

Distance is the obvious difference and it is not the main one.

The real constraints on a long route are the number of authorities involved, each with its own permit; the bridges and culverts on local roads that have never carried a load of that weight; the unsealed sections that become impassable after rain; and the limited options if a route is closed. Those are covered in [modular for regional and remote sites](/blog/modular-for-regional-and-remote-sites).

The last hundred metres

More deliveries are held up at the site frontage than anywhere on the route.

A verge too soft for a trailer, a power line across the entry, a street tree with a canopy at the wrong height, a kerb that cannot be mounted, a neighbour's parked vehicle. All local, all solvable with notice, and all expensive on the day.

Which is why the final approach is walked and measured, and why the crane position is confirmed against it, as described in [crane selection and lift planning](/blog/crane-selection-and-lift-planning).

How we deliver. Discuss a project.

MADEmodular / MADEbetter.