A transport consultancy buys Revit and sends its engineers on a course. Three months later it concludes that BIM does not suit roads.
That conclusion is wrong, though easy to understand. They took a tool built for buildings and pointed it at a road.
Infrastructure BIM rests on the same principle as building BIM: one shared information model. What differs is the object being modelled, the tools, and how the model is organised — enough to deserve its own discussion.
This article sets out the three basic differences, explains where Revit runs out, describes what Civil 3D does, then looks at the legal position.
Three basic differences
A building is a block standing on a column grid. It divides into storeys and sits on a more or less flat site.
Infrastructure is not like that. Roads, railways, bridges, drainage systems, platform grading for a new urban area — all differ in three ways.
Located by chainage, not by storey. A road is defined by three things: a horizontal alignment, a vertical profile, and a typical cross section. They run for tens of kilometres. There are no storeys and no column grid; everything is located by chainage. The model has to be generated from those three components. Raise the profile by thirty centimetres and the side slopes, ditches and volumes all shift with it.
Terrain is the main object. For a building, the ground is a single level. For infrastructure, the surveyed terrain surface is what the model clings to. The road cuts through hills, fills across fields, and drains along the natural gradient. Without a terrain surface there is no infrastructure model.
Cost sits in the earthworks. In a building, concrete and reinforcement account for most of the price. On a road they do not. Excavation, fill, hauling and ground treatment dominate, and all of them react sharply to a change in the profile. So infrastructure BIM revolves around computing cut and fill volumes section by section, balancing them, and updating the moment the design changes.
One more point. Infrastructure usually crosses several administrative areas and involves several organisations, with data tied to real geographic coordinates. That is why infrastructure BIM sits so close to GIS — close enough that the Institute runs a separate GIS with BIM course for planning and infrastructure people.
Where Revit runs out
Revit is built around storeys, grids and families placed at positions. What is Revit covers that in detail.
Point it at infrastructure and three limits appear.
- No alignment object. Revit has no horizontal alignment, no profile, no typical cross section, and no mechanism to generate a model along a route. Building a kilometre of road in Revit means modelling each stretch by hand, and redoing it when the profile changes.
- Weak terrain handling. Revit has basic terrain tools. They are fine for the grounds around a building. They are not enough for a surface of millions of points, slope and catchment analysis, or accurate earthwork volumes.
- Coordinates and extent. A Revit model behaves well within a few kilometres of its origin. Infrastructure runs for tens of kilometres on national coordinates, which brings geometric error and performance problems.
None of this makes Revit useless on an infrastructure project. It has a clear place.
That place is the point structures along the route: stations, toll plazas, pump houses, portal-frame overpasses, utility tunnels. And repeated members such as precast bridge girders.
The usual arrangement splits the work by type of object. Civil 3D takes the alignment and terrain. Revit or Tekla take the point structures. Navisworks or InfraWorks then federate everything for coordination. What Navisworks is used for covers that federation step.
What Civil 3D does
The short answer: Autodesk Civil 3D is AutoCAD plus a set of intelligent objects for infrastructure. What is Civil 3D? goes into how those objects stay linked to each other.
Those objects are surfaces, alignments, profiles, cross sections, corridor models, pipe networks and grading. They are linked to one another. Change the alignment and the profile, the corridor and the quantities follow. That linkage is the "BIM" part of the program.
Here is what Civil 3D does on a road project. It is also the sequence of the Institute's Civil 3D course, which runs 15 sessions.
- Project setup and survey data. Coordinate system, survey points, point clouds.
- Terrain surface. Build the existing surface, contours, slope and catchment analysis.
- Alignment and profile. Horizontal alignment with curves and superelevation. Existing ground profile and design profile.
- Cross sections and corridor model. A typical section of lanes, shoulders, ditches and side slopes. Run it along the alignment and you have a three-dimensional model of the road.
- Intersections, slopes and quantities. Junction handling, slopes tied to the terrain, cut and fill computed station by station.
- Pipe networks. Culverts, manholes and ditches with levels and gradients. Interference checks against structures, quantities for the bill.
- Grading and earthwork balance. Feature lines and grading for urban and industrial areas. Optimise platform levels to cut down on hauling.
- Drawings and data output. Plans, profiles and cross sections generated by chainage. Quantity tables. IFC export, or handover to InfraWorks and Navisworks.
The course suits road and infrastructure engineers who already work in 2D. They understand profiles and cross sections already. What they have to learn is a different habit of mind: one model generating every drawing, instead of drafting each cross section by hand.
What the law says about linear works
This is where people working in infrastructure most often get it wrong, so it is worth stating plainly.
Since 1 July 2026 the central instrument on BIM is Decree 217/2026/ND-CP. Point a, clause 1 of Article 8 requires BIM on all new works of grade II and above, from the feasibility study stage onwards. It draws no distinction by funding source.
But the decree carves out exceptions. The investment decision-maker may choose not to apply BIM to three groups: projects involving linear works, projects in areas of a special nature, and projects subject to state secrecy requirements.
Roads and railways are linear works. So most linear transport projects fall into that exception.
Two things are worth remembering about it.
First, it is a discretion, not an automatic exemption. The decision-maker may choose not to apply BIM — and may equally choose to apply it. Plenty of clients still require a model because it serves them.
Second, the exception speaks only to legal obligation. It says nothing about whether BIM is useful on infrastructure. The practical benefits stand: faster and more accurate earthwork quantities, clashes found between the route and buried services, options compared before a decision is taken.
The legal framework for BIM in Vietnam sets out the full chain of obligations under Article 8, including the requirement to submit BIM data at appraisal.
How Vietnamese infrastructure applies BIM
In practice, infrastructure BIM in Vietnam runs along three lines.
Roads and expressways. Alignment and terrain modelled in Civil 3D or an equivalent, used for quantities, option comparison, and coordination with services along the route. A growing number of projects feed the model into machine control on site.
Bridges. Girders, piers and abutments modelled in Revit, Tekla or dedicated bridge software, then combined with the alignment from Civil 3D. Strongest on complex reinforcement coordination, staged construction and precast member tracking. The analysis still happens in specialist software such as Midas Civil.
Technical infrastructure for urban and industrial areas. Platform grading, internal roads, drainage, water supply, power. This is where Civil 3D pays off most clearly, and where a good number of private developers already ask for a model to manage service connections.
The bottleneck is not the software but the people. Transport and infrastructure engineers know BIM far less well than building engineers. The reason is simple: BIM training in Vietnam grew out of buildings.
That is why the Institute runs a separate Infrastructure BIM Manager course over 8 sessions. It is aimed at people managing infrastructure projects, not at modellers. It covers BIM fundamentals for infrastructure, data management and model control, structuring a model that runs along a route, and coordination and clash resolution.
Frequently asked questions
Does a road engineer need Revit?
Not for the alignment. Only enough to read a model, in case the project has point structures built in Revit. Civil 3D should come first.
Are linear works exempt from BIM altogether?
Not quite. The investment decision-maker may choose not to apply it, but that is a discretion rather than an automatic exemption. Many clients still require a model for practical reasons.
Does Civil 3D replace AutoCAD?
Civil 3D contains the whole of AutoCAD. Anyone comfortable with AutoCAD will recognise the interface immediately. What is added is the infrastructure object set.
Do you need GIS to work in infrastructure BIM?
Not strictly, but it helps a great deal. Infrastructure projects sit on real geographic coordinates and cross several administrative areas. GIS makes the context and planning data far easier to handle.
Does an infrastructure project manager need to learn modelling?
No. Their job is to set requirements, control model quality and organise coordination. That is why the Infrastructure BIM Manager course is separate from the Civil 3D course.
Is infrastructure BIM so different that you start over?
No. The principle is the same: one shared model, information attached to objects, coordination between disciplines. What has to be relearned is the toolset and how a route-based model is organised.