Chartwell Drive Cardiff / Caerdydd, Cardiff
42 addresses across 2 postcodes (CF14), about 370 m long, classed as a local road. USRN 5800365.
- Sales: 38 recorded sales since 1995; in 2026 the median was £755,000 across 1 sale.
- Prices and rents: A typical home in Cardiff cost £272,443 in August 2026 (+2.1% on a year); private rents averaged £1,179 a month.
- Energy: 22 homes have an energy certificate (C: 8, D: 13, E: 1).
- Flood: No postcode centre on the street is in flood zone 2 or 3.
- Recorded floods: No recorded flood covers the centre of any of its postcodes.
- Radon: Up to 5 to 10% of homes in the 1 km squares around it are estimated to be at or above the radon Action Level.
- Traffic: The busiest counted road within 500 m (0.3 miles), the B4562, carries 5,563 motor vehicles a day on average (2025).
- Council tax: Most homes around it are in council tax band G; Band D in Cardiff costs £2,013 a year in 2026-27.
- Broadband: Gigabit broadband is available to 100% of premises.
- Transport: The nearest railway station is Llanishen, about 520 m (0.3 miles) away in a straight line.
- Green space: The nearest park or garden is about 380 m away.
- Air: Background air pollution in 2024 was 10.2 µg/m³ of nitrogen dioxide and 5.7 of PM2.5, within UK legal limits.
- Height: Its addresses are 55 to 61 m above sea level.
- Noise: 4 of its 42 addresses are modelled at 55 dB or more from road traffic.
- Doctors: The nearest GP surgery is Llanishen Court Surgery, about 1.2 km (0.7 miles) away, with 2 practices within 1.6 km (1 mile).
- People: About 340 people lived in the census areas around it in 2021; 98% of households owned their home and 61% of adults held a degree or other higher qualification.
- Crime: 6 crimes were recorded within 250 m between September 2025 and August 2026, most often violence and sexual offences.
- Road safety: No collisions in which someone was hurt were reported on and around it in 2021 to 2025.
£9.99 The Street Dossier Full Report for a home on Chartwell Drive: its own records, questions to ask the seller and everything on this page, in one PDF. Choose the home
House sales on this street
| Year | Sales | Median price | Lowest | Highest |
|---|---|---|---|---|
| 2026 | 1 | £755,000 | £755,000 | £755,000 |
| 2025 | 2 | £630,000 | £625,000 | £635,000 |
| 2023 | 3 | £550,000 | £524,000 | £585,000 |
| 2021 | 1 | £502,000 | £502,000 | £502,000 |
| 2019 | 1 | £382,500 | £382,500 | £382,500 |
| 2018 | 1 | £410,000 | £410,000 | £410,000 |
| 2016 | 2 | £330,000 | £280,000 | £380,000 |
| 2014 | 1 | £359,000 | £359,000 | £359,000 |
| 2012 | 3 | £344,000 | £160,000 | £400,000 |
| 2011 | 1 | £350,000 | £350,000 | £350,000 |
| 2009 | 2 | £305,000 | £300,000 | £310,000 |
| 2008 | 1 | £370,000 | £370,000 | £370,000 |
| Date | Address | Type | Price | Notes |
|---|---|---|---|---|
| 10 Jul 1998 | 2 CF14 0EZ | Detached | £130,000 | Leasehold. |
| 21 Jun 2019 | 4 CF14 0EZ | Detached | £382,500 | |
| 29 Aug 2025 | 6 CF14 0EZ | Detached | £625,000 | Leasehold. |
| 16 Nov 2012 | 6 CF14 0EZ | Detached | £344,000 | |
| 20 Apr 2016 | 8 CF14 0EZ | Detached | £280,000 | |
| 20 Dec 2000 | 8 CF14 0EZ | Detached | £140,000 | |
| 31 Jan 1997 | 8 CF14 0EZ | Detached | £101,500 | |
| 29 Jan 2021 | 9 CF14 0EZ | Semi-detached | £502,000 | |
| 30 Nov 2001 | 9 CF14 0EZ | Semi-detached | £130,000 | |
| 12 Dec 1997 | 9 CF14 0EZ | Detached | £135,000 | Leasehold. |
| 17 Aug 2018 | 12 CF14 0EZ | Detached | £410,000 | |
| 30 Nov 1999 | 12 CF14 0EZ | Detached | £800,000 | New build. |
| 24 Mar 2023 | 15 CF14 0EZ | Detached | £585,000 | |
| 4 Jun 2014 | 16 CF14 0EZ | Detached | £359,000 | |
| 26 Oct 1999 | 17 CF14 0EZ | Detached | £800,000 | New build. |
| 5 Feb 2026 | 18 CF14 0EZ | Detached | £755,000 | |
| 16 Jul 2008 | 18 CF14 0EZ | Detached | £370,000 | |
| 13 Jul 2007 | 20 CF14 0EZ | Detached | £362,000 | |
| 30 Sep 1996 | 21 CF14 0EZ | Detached | £149,950 | |
| 7 Dec 2011 | 22 CF14 0EZ | Detached | £350,000 | |
| 17 Oct 2003 | 22 CF14 0EZ | Detached | £266,000 | |
| 24 Feb 1995 | 24 CF14 0EZ | Detached | £102,000 | |
| 29 May 2009 | 25 CF14 0EZ | Detached | £310,000 | |
| 25 Aug 2023 | 26 CF14 0EZ | Detached | £550,000 | |
| 31 Oct 2016 | 27 CF14 0EZ | Detached | £380,000 | |
| 23 Mar 2012 | 27 CF14 0EZ | Detached | £400,000 | |
| 14 Nov 2003 | 27 CF14 0EZ | Detached | £276,000 | |
| 21 Jul 1999 | 27 CF14 0EZ | Detached | £145,000 | |
| 7 Aug 2009 | 29 CF14 0EZ | Detached | £300,000 | |
| 25 Jul 2006 | 29 CF14 0EZ | Semi-detached | £280,000 | Leasehold. |
| 27 Sep 2023 | 32 CF14 0EZ | Detached | £524,000 | |
| 28 Aug 2025 | 33 CF14 0EZ | Detached | £635,000 | |
| 11 Jun 1999 | 33 CF14 0EZ | Detached | £141,000 | |
| 1 Jun 2007 | 35 CF14 0EZ | Detached | £365,000 | |
| 1 Aug 1997 | 35 CF14 0EZ | Detached | £135,000 | |
| 17 Jul 1998 | 37 CF14 0EZ | Detached | £157,500 | Leasehold. |
| 16 Oct 2025 | PROTEA LODGE CF14 0EZ | Other | £760,000 | Not a standard sale (repossession, buy-to-let or transfer). |
| 21 Sep 2012 | PROTEA LODGE CF14 0EZ | Detached | £160,000 |
House prices and rents in Cardiff
A typical home in Cardiff cost £272,443 in August 2026, 2.1% more than a year before. That is 16% more than five years earlier and 43% more than ten years earlier.
| Home | Typical price, Aug 2026 |
|---|---|
| Detached | £515,292 |
| Semi-detached | £324,962 |
| Terraced | £262,795 |
| Flat or maisonette | £161,334 |
| Bought by a first-time buyer | £234,533 |
Private renters in Cardiff paid £1,179 a month on average in September 2026, 3.2% more than a year before. That is 37% more than five years earlier.
| Home | Average rent a month, Sep 2026 |
|---|---|
| One bedroom | £910 |
| Two bedrooms | £1,086 |
| Three bedrooms | £1,212 |
| Four or more bedrooms | £1,705 |
Energy performance certificates
22 homes with a current certificate; median floor area 141 m². Most common: House, detached (21); Bungalow, detached (1). Built: 1976-1982 (17); 1983-1990 (4); 2012 onwards (1). Tenure at assessment: owner-occupied (18); rented (private) (1).
Each home's certificates and sales (22 addresses)
- 1 Chartwell Drive, Lisvane
- 4, Chartwell Drive, Lisvane
- 6 Chartwell Drive, Lisvane
- 7, Chartwell Drive, Lisvane
- 8, Chartwell Drive, Lisvane
- 9, Chartwell Drive, Lisvane
- 12, Chartwell Drive, Lisvane
- 15 Chartwell Drive, Lisvane
- 16, Chartwell Drive, Lisvane
- 18 Chartwell Drive, Lisvane
- 21, Chartwell Drive, Lisvane
- 22, Chartwell Drive, Lisvane
- 25, Chartwell Drive, Lisvane
- 26, Chartwell Drive, Lisvane
- 27 Chartwell Drive, Lisvane
- 28, Chartwell Drive, Lisvane
- 29, Chartwell Drive, Lisvane
- 32 Chartwell Drive, Lisvane
- 33 Chartwell Drive, Lisvane
- 39 Chartwell Drive, Lisvane
- 41 Chartwell Drive, Lisvane
- Protea Lodge, Chartwell Drive, Lisvane
Gas and electricity use
Homes with gas used 16,815 kWh of it on average in 2024, 46% more than the district's 11,529 kWh, and 4,512 kWh of electricity, 45% more than the district's 3,105 kWh. There are gas meters for about 100% of the homes.
| Postcode | Electricity meters | Typical electricity | Gas meters | Typical gas |
|---|---|---|---|---|
| CF14 0EZ | 37 | 3,494 kWh | 39 | 15,836 kWh |
| CF14 0EQ | 5 | 5,335 kWh | 5 | 34,306 kWh |
These are all the homes on each postcode, whatever their size and however many live in them, so they show the kind of homes and heating here rather than what any one home uses. The typical figure is the median: half the homes used less. The district is CF14.
Council tax
What each band costs in Cardiff in 2026-27: Band D £2,013 a year on average, including the police and community council charges.
| A | B | C | D | E | F | G | H | I |
|---|---|---|---|---|---|---|---|---|
| £1,342 | £1,566 | £1,789 | £2,013 | £2,461 | £2,908 | £3,355 | £4,026 | £4,697 |
Homes by band in the neighbourhood around this street: most are in band G (39% of about 1,340 homes).
Planning and heritage
- Conservation area: no postcode centre in this street's postcodes is in one.
- Listed buildings on or by this street: none.
- Article 4 directions, tree preservation orders and green belt: Wales has no national record of these; the council's planning department holds them.
Energy projects nearby
No wind turbine or waste plant within 5 km (3.1 miles), and no solar farm, battery site or other project of 1 MW or more within 2 km (1.2 miles), of the street's postcodes, operating or planned.
Roadworks
Street works permits come from the Department for Transport's Street Manager, which covers England only.
Flood risk
Rivers, the sea or surface water: of the 48 address points in this street's postcodes, 0 at high risk, 0 at medium risk and 1 at low risk. Each counts once, at the higher of its rivers-and-sea and surface-water risk.
Rivers and the sea alone: none is in an area at risk. Surface water and small watercourses alone: 0 at high risk, 0 at medium risk and 1 at low risk.
High: 3.3% (1 in 30) or more chance of flooding a year. Medium: 1% to 3.3%. Low: 0.1% to 1%. The map allows for flood defences. Address points are every property record (UPRN) in the postcode, each counted if it is in an area or within 5 m of one (the maps stop at building walls); a few are not homes, such as garages, business units or caravan pitches. Counts cover whole postcodes, which can include other streets.
Flood zone for planning: no postcode centre on this street is in flood zone 2 or 3. Welsh zones include an allowance for climate change.
| Postcode | Planning zone | Addresses at high / medium / low risk |
|---|---|---|
| CF14 0EZ | not in 2 or 3 | 0 / 0 / 1 |
| CF14 0EQ | not in 2 or 3 | 0 / 0 / 0 |
Recorded floods
No recorded flood covers the centre of any of this street's postcodes.
Recorded floods are where floodwater was seen or surveyed after a flood. Many floods were never mapped, an outline over a postcode's centre does not mean every home in it flooded, and homes outside one may have. Ask the seller whether the home itself has flooded.
Coastal erosion
No projected coastal erosion zone is within 1 km (0.6 miles) of the street's postcodes.
Storm overflows
No storm overflow outlet is within 1 km (0.6 miles) of the street's postcodes in this record, which covers the overflows reported to the Environment Agency: most of Wales's are reported to Natural Resources Wales instead.
Coal mining
No postcode centre on the street is in a coalfield: the Mining Remediation Authority records no coal mining risk here.
Radon
The highest radon potential in the 1 km squares around the street's postcodes is 5 to 10%: up to that share of homes there is estimated to be at or above the Action Level of 200 becquerels per cubic metre. At least part of that area is a radon Affected Area, where 1% or more of homes are.
Radon is a natural radioactive gas from the ground that can build up indoors; long exposure raises the risk of lung cancer. A three-month test with two small detectors is the only way to know a home's level, and a high level can usually be brought down with a sump or better ventilation. Homes built here in recent decades should have radon protection under the building regulations (basic protection from 3%, full protection from 10%). UKHSA sells a radon report for a single address from its detailed map at ukradon.org.
Historic landfill
No historic landfill site is within 500 m (0.3 miles) of the street's postcodes.
Height above sea level
The street's 42 addresses are between 55 m and 61 m above sea level (59 m on average); the ground rises about 6 m from the lowest to the highest.
Broadband
| Postcode | Superfast (30 Mbit/s+) | Ultrafast (300 Mbit/s+) | Gigabit | Below 10 Mbit/s |
|---|---|---|---|---|
| CF14 0EQ | 100% | 100% | 100% | 0% |
| CF14 0EZ | 100% | 100% | 100% | 0% |
Getting around
| Nearest | Distance | |
|---|---|---|
| Railway stations | Llanishen 226,000 journeys in 2024–25 | 520 m (0.3 miles) |
| Lisvane and Thornhill 241,000 journeys in 2024–25 | 1.2 km (0.7 miles) | |
| Ty Glas 94,000 journeys in 2024–25 | 2.1 km (1.3 miles) | |
| Bus stops | 7 stops within 400 m (0.2 miles), 22 within 800 m (0.5 miles); nearest Chartwell Drive Lisvane | 180 m |
| Bus or coach station | Caerphilly Interchange Stand 11 | 4.9 km (3.1 miles) |
| Ferry terminal | Cardiff Castle Waterbus Stop | 6 km (3.7 miles) |
| Car parks | Cyncoed Campus Car Park | 3 km (1.8 miles) |
| EV charging points | Osprey Charging Station | 1.8 km (1.1 miles) |
| Airport with scheduled flights | Cardiff International Airport CWL | 19.3 km (12 miles) |
Local services
| Nearest | Distance | |
|---|---|---|
| GP surgeries | 2 practices within 1.6 km (1 mile); nearest Llanishen Court Surgery | 1.2 km (0.7 miles) |
| Pharmacies | 4 pharmacies within 1.6 km (1 mile); nearest M W Phillips Chemists | 1.2 km (0.7 miles) |
| NHS dentists | 2 practices within 1.6 km (1 mile); nearest Cedars Dental Surgery | 1 km (0.6 miles) |
| Hospital | Bft Southmead University Hospital Of Wales | 3.2 km (2 miles) |
| Police station | Llanishen Police Station | 1 km (0.6 miles) |
| Cash machines | The Cooperative Food Cardiff - Cyncoed Road, Cyncoed | 1.4 km (0.9 miles) |
Parks and green space
| Nearest | Distance | |
|---|---|---|
| Park or garden | 4 within 800 m (0.5 miles); nearest Unnamed 7.1 ha | 380 m |
| Largest park within 800 m (0.5 miles) | Unnamed 15 ha | 710 m (0.4 miles) |
| Play area | 2 within 800 m (0.5 miles); nearest Unnamed 900 m² | 410 m (0.3 miles) |
| Playing field | 1 within 800 m (0.5 miles); nearest Unnamed 1.5 ha | 520 m (0.3 miles) |
| Allotments | 1 within 800 m (0.5 miles); nearest South Rise Allotments 3.1 ha | 290 m |
Within 800 m (0.5 miles): 4 parks and gardens, 35 hectares in all.
Landmarks
The nearest historic landmark is Ty Gwyn, a registered park or garden (Grade II*), 470 m (0.3 miles) north-east. 12 listed buildings are within 1 km (0.6 miles), 1 of them Grade II*.
| Name | What it is | From the middle of the street |
|---|---|---|
| Ty Gwyn | Registered park or garden, Grade II* | 470 m (0.3 miles) north-east |
| Church of St Denys | Listed building, Grade II* | 830 m (0.5 miles) north-east |
| Parc Cefn Onn | Registered park or garden, Grade II | 1.8 km (1.1 miles) north-west |
| Name | What it is | From the middle of the street |
|---|---|---|
| Coed-ty-llwyd | Wood | 290 m south-east |
| Coedyfelin | Wood | 650 m (0.4 miles) north-west |
| Llanishen Reservoir | Lake or reservoir | 750 m (0.5 miles) south |
| Rhydypennau Wood | Wood | 1 km (0.6 miles) south-east |
| Craig Llysfaen | Hill | 2.6 km (1.6 miles) north |
| Cwm Nofydd | Valley | 3.5 km (2.2 miles) west |
Air quality
| Pollutant | Here | UK limit | WHO guideline |
|---|---|---|---|
| Nitrogen dioxide (NO2) | 10.2 | 40 | 10 |
| Fine particles (PM2.5) | 5.7 | 20 | 5 |
| Particles (PM10) | 9.0 | 40 | 15 |
All three are within the UK legal limits; nitrogen dioxide and PM2.5 are above the WHO guideline, as in most towns and cities.
Road and rail noise
| Level | Road traffic | Railways |
|---|---|---|
| 60 to 64 | 1 | 0 |
| 55 to 59 | 3 | 0 |
| Under 55 | 38 | 42 |
4 of the street's 42 addresses are modelled at 55 dB or more from road traffic, above the WHO guidelines.
Climate, daylight and earthquakes
Monthly temperatures and rainfall, sunrise and sunset through the year, and earthquakes recorded nearby since 1970 are much the same across the area, so they are worked out once for Cardiff: see them on the Cardiff page.
Nearest schools
| School | Phase | Ages | Distance | Inspection | Exam results |
|---|---|---|---|---|---|
| Christ the King Primary School Roman Catholic English medium | Primary | 4–11 | 630 m (0.4 miles) | Estyn reports · My Local School | Not published in Wales |
| Llysfaen Primary School English medium | Primary | 4–11 | 740 m (0.5 miles) | Estyn reports · My Local School | Not published in Wales |
| Llanishen High School English medium | Secondary | 11–19 | 900 m (0.6 miles) | Estyn reports · My Local School | Not published in Wales |
| Coed Glas Primary School English medium | Primary | 3–11 | 1 km (0.6 miles) | Estyn reports · My Local School | Not published in Wales |
| Corpus Christi Catholic High School Roman Catholic English medium | Secondary | 11–16 | 1.1 km (0.7 miles) | Estyn reports · My Local School | Not published in Wales |
| Thornhill Primary School English medium | Primary | 3–11 | 1.5 km (0.9 miles) | Estyn reports · My Local School | Not published in Wales |
| Rhydypenau Primary School English medium | Primary | 3–11 | 1.5 km (0.9 miles) | Estyn reports · My Local School | Not published in Wales |
| Ysgol Y Wern Welsh medium | Primary | 3–11 | 1.8 km (1.1 miles) | Estyn reports · My Local School | Not published in Wales |
| Glyncoed Primary School English medium | Primary | 3–11 | 2 km (1.2 miles) | Estyn reports · My Local School | Not published in Wales |
| Cardiff High School English medium | Secondary | 11–19 | 2 km (1.2 miles) | Estyn reports · My Local School | Not published in Wales |
Exam results are from the Department for Education's school performance tables (Explore Education Statistics, Open Government Licence), for all pupils at each school. The middle school in England had 63% at the expected standard at the end of primary school (2025), Attainment 8 of 46.0 at GCSE (2026) and an A level average of C+ (2025). Attainment 8 adds up a pupil's grades in eight GCSEs, with English and maths counted twice (90 is the most), averaged over the school's pupils. Progress 8 compares pupils with others who had the same results at the end of primary school; it is not published for GCSEs in 2025 and 2026, as those pupils sat no primary tests during the pandemic. Small year groups swing from year to year, and figures for very small ones are withheld. Wales publishes no school results tables.
Nurseries and childcare
Ofsted registers childcare in England only. In Wales, nurseries, playgroups and childminders are registered and inspected by Care Inspectorate Wales, whose directory of services lists them with their reports.
Food hygiene ratings nearby
| Business | Type | Distance | Rating | Rated |
|---|---|---|---|---|
| Llanishen and Lisvane Visitor Attraction Centre CF14 0SD | Restaurant/Cafe/Canteen | 430 m (0.3 miles) | 5 Very good | 1 Oct 2026 |
| Acorns Nursery Llanishen CF14 0SA | Hospitals/Childcare/Caring Premises | 480 m (0.3 miles) | 5 Very good | 22 Oct 2026 |
Crime within 250 m
| Category | Crimes |
|---|---|
| Violence and sexual offences | 3 |
| Anti-social behaviour | 1 |
| Vehicle crime | 1 |
| Public order | 1 |
Most of these are attached to: On or near Cwrt Cefn (3); On or near Mill Close (1); On or near Woodside Court (1); On or near Balmoral Close (1).
Road safety
No collisions in which someone was hurt were reported on and around the street in 2021 to 2025.
Only collisions in which someone was hurt and which the police were told about are here: damage-only collisions and near misses are not, and some injuries are never reported. Positions are recorded by the police, usually to within a few metres. Each year's figures are published the following September.
Traffic on nearby roads
The busiest counted road within 500 m (0.3 miles) is the B4562, with 5,563 motor vehicles a day on average in 2025, 240 m from the street's postcodes.
| Road | Between | Vehicles a day | Lorries | Ten years before | Distance |
|---|---|---|---|---|---|
| B4562 | Not recorded | 5,563 counted 2025 | 2% | 240 m |
Each figure is the annual average daily flow: the motor vehicles passing the count point, both ways, on an average day of the year. A point is counted by hand on a weekday every few years and estimated from the trend on similar roads in between. Lorries are heavy goods vehicles, as a share of all motor vehicles.
People and work
Who lives here
| Around this street | Wales | |
|---|---|---|
| Median age | 48 | 43 |
| Children under 15 | 18% | 17% |
| Aged 65 and over | 25% | 21% |
Homes
| Around this street | Wales | |
|---|---|---|
| Owned (outright or with a mortgage) | 98% | 66% |
| Owned outright | 59% | 38% |
| Shared ownership | 0% | under 1% |
| Social rented | under 1% | 17% |
| Private rented | 2% | 17% |
Work and commuting
| Around this street | Wales | |
|---|---|---|
| Adults (16 and over) in work | 56% | 54% |
| Unemployment (of those working or looking for work) | 5% | 6% |
| Retired (of adults) | 31% | 25% |
| Long-term sick or disabled (of adults) | 2% | 6% |
| Work mainly from home (of those in work) | 40% | 26% |
| Travel to work by car or van | 54% | 61% |
| By train, Underground, metro or tram | 1% | under 1% |
| By any public transport, including bus | 1% | 3% |
| On foot or by bicycle | 3% | 8% |
| Work within 10 km (6 miles) of home (of those who travel to work) | 68% | 60% |
| Work 30 km (19 miles) or more away | 12% | 10% |
Education and languages
| Around this street | Wales | |
|---|---|---|
| Degree or other higher qualification, Level 4+ (of adults) | 61% | 32% |
| No qualifications | 4% | 20% |
| Apprenticeship as highest qualification | 1% | 6% |
| Main language English or Welsh (aged 3 and over) | 99% | 97% |
| Cannot speak English well or at all | under 1% | under 1% |
Deprivation
The neighbourhood around this street is in decile 9 of 10 on the Welsh Index of Multiple Deprivation 2025, where 1 is the most deprived tenth of Wales's 1,917 neighbourhoods and 10 the least.
What has changed
- Food hygiene ratings Acorns Nursery Llanishen (hospitals/childcare/caring premises, CF14 0SA) re-inspected, still 5 Very good (rated 22 October 2026) found 5 November 2026
Postcodes on this street
Nearby streets
Longleat Close · Buckingham Close · Wood Close · Tanglewood Close · Crofta · Balmoral Close · Cwrt Cefn · Woodside Court · Barbrook Close · Millgate · Portland Place · Mill Close
What this page cannot tell you
- Whether a particular house is at risk of flooding, subsiding or anything else: the flood map is a model of areas and there is no property-level data here.
- What a home is worth now: sales are historic prices for the homes that happened to sell.
- How safe the street is: crime points are moved to anonymised locations and many crimes are never reported; road collisions count only those in which someone was hurt and the police were told.
- Whether you would get a place at a school: distances are straight lines, not catchments.
- Who lives on the street now: census figures describe the small areas around it in March 2021, during a lockdown.
- How long a journey takes or how often anything runs: transport distances are straight lines to the nearest stops.
- Whether a GP practice is taking new patients, or a dentist new NHS patients.
- How loud a home is inside, or noise from industry, neighbours or smaller airfields: noise figures are models of road, rail and air traffic outside.
How each figure on this page is matched to the street and worked out: methodology.