Why does transport outweigh energy or catering at most events?

Because it involves moving thousands of people within a very short window of hours, almost always by private car at low occupancy. Venue energy and catering, by comparison, affect a much more controlled space and number of suppliers.

What average vehicle occupancy is used if I don't have real data?

Without your own data, most calculations use a generic figure around 1.5 people per car. It's a reasonable approximation in the absence of anything better, but it understates the real room for improvement: with active carpooling, that figure can rise measurably.

How much can average occupancy improve with a carpooling programme?

It depends on the event and how early the option is communicated, but every person added to a trip that was already happening directly reduces the number of cars needed to move the same number of attendees.

What target should I set in my transport emissions reduction plan?

A specific, measurable transport target — say, a percentage improvement in average occupancy or shared kilometres versus the previous edition — works better than a generic "be more sustainable" goal, because it can be verified with data once the event is over.

Can VIB3S's data justify the reduction plan to a sponsor?

Yes. Because they're calculated from real trips (not estimates), shared kilometres, cars avoided and CO₂ reduced per date are the kind of data a sponsor or sustainability auditor can verify.

Guide for organizers

Attendee transport emissions

When an event properly measures its carbon footprint, it almost always finds the same thing: attendee transport outweighs every other category, including energy, catering and waste combined.

It's the biggest part of the problem — and also the one that responds fastest to a well-designed reduction plan.

Aerial view of a parking lot with cars parked in rows, many of them generating transport emissions

Why attendee transport is an event's biggest source of emissions

An event moves thousands of people to the same point within a few hours — usually by private car and at low occupancy (1-2 people per vehicle if nothing is done to change it). That travel pattern is, by design, inefficient.

Unlike venue energy or catering, which an organiser can control directly (choosing a supplier, a renewable energy contract), transport depends on a decision each attendee makes separately. That's why it's usually the hardest category to reduce without a tool that coordinates those individual decisions.

How your audience's transport emissions are calculated

The calculation combines three data points per attendee (or, more realistically, per representative sample): distance travelled from their origin, transport mode used, and vehicle occupancy if travelling by car.

The hardest piece to get is usually real vehicle occupancy — without real trip data, most calculations assume a generic average occupancy (1.5 people per car is a common figure) that rarely reflects what actually happens at a specific event.

When a carpooling platform is active at the event, that part of the calculation stops being an estimate: it can be measured directly from real trips posted and completed.

An electric car plugged into a charging point, as an emissions reduction measure

A plan to reduce transport emissions

A transport emissions reduction plan that actually works relies on a few measures applied consistently edition after edition, rather than many one-off actions:

Set a measurable target (e.g. raise average vehicle occupancy by X% versus the previous edition) instead of a generic goal to "reduce emissions".
Activate carpooling early enough that attendees factor it into how they decide to arrive, not as a last-minute option.
Reinforce public transport or shuttles at the peak-demand time slots identified from the previous edition's data.
Measure the real outcome (shared kilometres, cars avoided, CO₂ reduced) and compare it against the target you set at the start — not just against the previous edition in the abstract.

Carpooling's role in your reduction plan

Carpooling is the fastest transport-emissions reduction measure to activate because it doesn't depend on contracting new infrastructure or on attendees switching transport mode: it just asks them to share the trip they were already going to make.

With VIB3S, that gets measured from the very first trip posted — shared kilometres and CO₂ avoided, broken down by date — making carpooling the easiest part of a reduction plan to prove with real numbers to a sponsor, a city council, or in the event's sustainability report.

Event types