Vehicle swept path & tracking

Swept-path analysis, built in: pick a design vehicle, click a route, and watch the true swept envelope — with the same drive-line conventions an engineer uses in AutoTrack, and the answer to the question that matters: does it get round, and what does it need to do it?

Running a sweep (🚚)

Pick Checks ▸ Vehicle sweep, choose a vehicle, and click points along a route. The path follows the road centreline between your clicks — two clicks can cover a whole street — and turns between roads are rounded at a drivable radius. Esc clears the route. The sweep stays on the plan when you leave the tool, and clears itself if the roads change.

The swept envelope is the ground the vehicle body actually covers: the rear axle cuts inside the front on every turn and the front overhang sweeps wide, from a pure-pursuit tractrix simulation — not a stencil. Anywhere the envelope leaves the carriageway is marked red; a route tighter than the vehicle's steering lock is flagged.

The vehicles

Refuse vehicle (11.2 m) · fire appliance (8.3 m) · private car (4.8 m) · rigid HGV (12.0 m) · articulated HGV (16.5 m) · articulated LST (18.55 m — the UK Longer Semi-Trailer). An articulated vehicle's trailer is simulated as its own kinematic stage — the bogie chasing the kingpin — so trailer cut-in through corners is real physics, not sketched.

Drive-line conventions

Three, matching real swept-path practice. Left lane + swing out (UK) — the default — is how an engineer draws a real drive line: approach in the centre of the left lane, and where a bend's off-tracking demands it, borrow toward the driver's right (always the right — driving on the left, the vulnerable side is always the left kerb: the rear cuts in on a left-hander, the front swings out on a right-hander), then return to lane. The analysis reports how many metres of the route borrow the opposing lane. Hold left lane is strict lane discipline — it shows where holding the line is simply impossible. Centre of road is the worst-case manoeuvre using the full carriageway width — the accepted governing check for large vehicles on access streets, where Manual for Streets expects a refuse vehicle to straddle the centreline at low speed. Run all three and you have the full story: can it get round at all, can it stay in lane, and where must it swing.

Watch it drive

A playback bar appears in both views whenever a sweep is on the plan — play/pause, restart, scrub and speed (½–4×; 1× ≈ a cautious 5 mph) are shared, so switching views picks up mid-route. In 2D the vehicle drives the plan as a true-scale outline, tractor and trailer hinging independently. In 3D the envelope lies on the carriageway, the wheel paths trace the turn as painted lines, the front wheels visibly steer into each corner — and the refuse truck brings its crew, two loaders chasing along behind with wheelie bins in tow.

In the exports

With a sweep on screen, the PDF report adds a Vehicle Swept Path sheet — the B&W sketch base with just the envelope, plus the vehicle, drive-line convention, route length, opposing-lane use and any conflicts.