Methodology

Counter Data Sources

Ride counts come from automated cycle counters operated by each city council. For a full list of sources and external links, see the Data Sources page.

All counts are cyclists only — e-scooters, pedestrians, and other modes are excluded from the source data and are not counted in any figures on this site.

Wellington uses VivaCity video sensors, which expose multiple virtual “countlines” per camera. Raw totals include duplicate countlines that count the same cyclist more than once. See Wellington Counter Methodology for how we deduplicate these before calculating any figures.

Why these numbers are probably an undercount

Automated counters only measure cycling at the specific locations where they are installed. Any route without a counter is invisible to this dashboard — which means a significant share of real cycling activity is simply not captured.

The 2023 Census (main means of travel to work) gives a counter-independent cross-check. Christchurch recorded a 3.8% commuter cycling mode share (~5,700 workers cycling to work), and Wellington 3.1% (~3,200 workers) — roughly 3–4× the national average of 1.0%. The counter feeds on this site capture only the riders who happen to pass a sensor on a counted route. The true cycling population in each city is larger.

The Ministry of Transport Household Travel Survey (2023–24) adds further context: 27% of Christchurch residents and 22% of Wellington residents reported cycling at least once in the past month — including recreational, school, and errand trips that counters mostly miss.

In short: the impact figures on this site reflect only what the counters see. The real numbers are higher. This is another reason all calculations use the conservative 35% car substitution rate — the intent is to be defensible, not to claim more than the data supports.

Census source: Stats NZ, 2023 Census — Main means of travel to work (SA2-level origin-destination data). HTS source: Ministry of Transport, Household Travel Survey 2023–24.

Core Assumptions

Every calculation on this site shares a common set of NZ-specific constants. These are applied consistently so the numbers are comparable across widgets and cities.

• 35% — Car substitution rate (Conservative NZTA mode-shift estimate — only 35% of bike trips counted as replacing a car journey)
• 4.5 km — Average cycle trip (NZ Transport Agency national average)
• 10 L/100 km — Car fuel efficiency (Average NZ passenger car)
• 200 g CO₂/km — Fleet emissions (NZ light vehicle fleet average, 2026)
• $5.50 — Flat white price (NZ café market average, 2024)
• 5.5 m — Car length (Average car + bumper-to-bumper gap)
• 22 kg/year — Tree CO₂ absorption (Mature tree annual sequestration — Woodland Trust)
• 13.5 m² — Parking space (Per stall including access aisle — NZ Parking Association standard)
• 100 mg/km — Tyre dust (Particles shed per vehicle per km — range 50–200 mg/km)
• $0.50/km — Health benefit (NZD avoided healthcare cost per km cycled — ages 15–64, NZ-specific)

Fuel price is fetched live from MBIE weekly averages and falls back to $3.20/L if unavailable.

Daily City Savings

The dollar amount the city saves daily by cycling instead of driving.

trips × 35% × 4.5 km × (petrol $/L × 10 L ÷ 100) = $ saved

The 35% substitution rate is the key lever — it means we only count trips that plausibly replaced a car journey. The remaining 65% of rides (recreation, trips from households without cars, etc.) are excluded.

Carbon Saved

CO₂ not emitted by cars that stayed in the garage.

trips × 35% × 4.5 km × 0.200 kg CO₂/km = kg CO₂ avoided

tree equiv = CO₂ kg ÷ 22 kg/tree/year

The tree equivalent is the number of trees that would need to grow for a full year to absorb the same amount of carbon — not a count of trees planted.

Flat White Index

Fuel savings redenominated in flat whites — money that stayed in local cafés rather than going to offshore oil companies.

daily fuel savings ÷ $5.50 per flat white = coffees not bought from petrol companies

Public Health Value

The avoided healthcare cost from cycling instead of sitting in a car.

rolling 365-day trips × 35% × 4.5 km × $0.50/km = $ avoided healthcare cost (annual)

The card displays a rolling 365-day total — the sum of all counter readings over the past year. This is seasonally stable (unlike a year-to-date figure that shrinks to near-zero each January) and is directly equivalent to an annual total with no extrapolation needed. The $0.50/km figure captures reduced rates of cardiovascular disease, type 2 diabetes, and premature mortality for working-age adults (15–64). It shifts the argument from personal fuel savings to taxpayer savings.

Source: Bassett, D. et al. (2020). “Variations in the health benefit valuations of active transport modes by age and ethnicity: A case study from New Zealand.” Journal of Transport & Health, 19, 100953. doi:10.1016/j.jth.2020.100953

Road Space Saved (Invisible Traffic Jam)

If every cyclist had driven instead, today's extra cars would form a bumper-to-bumper queue. This is that queue — the one that didn't happen.

trips × 35% × 5.5 m per car ÷ 1,000 = km of phantom traffic jam

Parking Spaces Freed

Car parks that went unused because cyclists don't need them.

trips × 35% = spaces freed
spaces × 13.5 m² = land not paved

The 13.5 m² figure includes the access aisle per stall as per NZ Parking Association standards — not just the stall footprint.

Microplastic Tyre Dust Avoided

Tyre and road wear particles (TRWP) are a leading source of microplastic pollution in urban waterways. Every car trip not taken means less rubber shed on the road.

trips × 35% × 4.5 km × 0.1 g/km = grams of tyre dust not shed

Source: Baensch-Baltruschat, B., Kocher, B., Stock, F., & Reifferscheid, G. (2020). “Tyre and road wear particles (TRWP) — A review of generation, properties, emissions, human health risk, ecotoxicity, and fate in the environment.” Science of The Total Environment, 733, 137823.

Hardcore Kiwi Factor (Resilience Score)

How much cycling persists on bad-weather days compared to fair days.

(avg rides on bad-weather days ÷ overall daily avg) × 100 = score %

A bad weather day is defined as any day with rain ≥ 5 mm, wind gusts ≥ 50 km/h, or max temperature ≤ 8°C. Each day is compared to its seasonal baseline (mean ridership in the ±30 days around it) to correct for summer/winter variation — a rainy July isn't unfairly compared to a sunny January. The score is computed over the last 12 months so seasonal cities (e.g. Auckland) always have a meaningful sample of rough days.

Weather data: Open-Meteo archive API, timezone Pacific/Auckland.

Annual Bike Bonus (ROI Calculator)

Personal fuel savings from commuting by bike instead of driving.

km × 2 (round trip) × days/week × 52 weeks = annual km
annual km × (petrol $/L × 10 L ÷ 100) = annual savings
savings ÷ $5.50 = flat whites
annual km × 0.200 kg/km = CO₂ avoided
CO₂ ÷ 22 = trees equivalent

Unlike the city-wide metrics, this calculator does not apply the 35% substitution rate — because if you're using the slider, you are the person switching modes.

What these numbers don't capture

• Recreational and leisure cycling (counter placement and time-of-day patterns skew toward commuters)
• Trips that replaced public transport, walking, or e-scooters
• Economic activity generated by cycling (cafés, bike shops, tourism)
• Infrastructure savings (lower wear on roads, reduced need for car parking)
• Reduced congestion externalities

In other words, these numbers understate the real impact. The 35% substitution rate is a floor, not a ceiling.