Garden Close St Albans
9 addresses across 2 postcodes (AL1), about 100 m long, classed as a local road. USRN 37306686.
- Sales: 12 recorded sales since 1995; in 2026 the median was £588,000 across 1 sale.
- Prices and rents: A typical home in St Albans cost £655,974 in August 2026 (+3.2% on a year); private rents averaged £1,934 a month.
- Energy: 6 homes have an energy certificate (C: 1, D: 5).
- Flood: 3 addresses on its postcodes are in areas at high or medium risk of flooding from rivers, the sea or surface water.
- Recorded floods: No recorded flood covers the centre of any of its postcodes.
- Radon: Up to 1 to 3% of homes in the 1 km squares around it are estimated to be at or above the radon Action Level.
- Council tax: Most homes around it are in council tax band E; Band D in St Albans costs £2,419 a year in 2026-27.
- Broadband: Gigabit broadband is available to 100% of premises.
- Transport: The nearest railway station is St Albans City, about 1.5 km (0.9 miles) away in a straight line.
- Green space: The nearest park or garden, Marshalswick Recreation Ground, is about 250 m away.
- Air: Background air pollution in 2024 was 10.7 µg/m³ of nitrogen dioxide and 7.6 of PM2.5, within UK legal limits.
- Height: It is about 97 m above sea level.
- Noise: 1 of its 9 addresses is modelled at 55 dB or more from road traffic.
- Doctors: The nearest GP surgery is Hatfield Road Surgery, about 1.6 km (1 mile) away.
- People: About 680 people lived in the census areas around it in 2021; 92% of households owned their home and 71% of adults held a degree or other higher qualification.
- Crime: 15 crimes were recorded within 250 m between September 2025 and August 2026, most often other theft.
- Road safety: 1 collision in which someone was hurt was reported on and around it in 2021 to 2025.
£9.99 The Street Dossier Full Report for a home on Garden Close: 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 | £588,000 | £588,000 | £588,000 |
| 2024 | 1 | £620,000 | £620,000 | £620,000 |
| 2019 | 1 | £526,000 | £526,000 | £526,000 |
| 2018 | 1 | £535,000 | £535,000 | £535,000 |
| 2015 | 1 | £487,500 | £487,500 | £487,500 |
| 2012 | 2 | £374,500 | £360,000 | £389,000 |
| 2005 | 1 | £220,000 | £220,000 | £220,000 |
| 2004 | 1 | £272,000 | £272,000 | £272,000 |
| 2003 | 1 | £250,000 | £250,000 | £250,000 |
| 2001 | 1 | £171,000 | £171,000 | £171,000 |
| 1995 | 1 | £102,500 | £102,500 | £102,500 |
| Date | Address | Type | Price | Notes |
|---|---|---|---|---|
| 29 Oct 2004 | 1 AL1 4TX | Terraced | £272,000 | |
| 7 Dec 2012 | 3 AL1 4TX | Terraced | £389,000 | |
| 29 Apr 2005 | 3 AL1 4TX | Terraced | £220,000 | |
| 29 Feb 2024 | 4 AL1 4TX | Terraced | £620,000 | |
| 23 Nov 2012 | 4 AL1 4TX | Terraced | £360,000 | |
| 29 Jul 2015 | 5 AL1 4TX | Terraced | £487,500 | |
| 14 Mar 2018 | 6 AL1 4TX | Terraced | £535,000 | |
| 28 May 2003 | 6 AL1 4TX | Terraced | £250,000 | |
| 21 Jun 2001 | 6 AL1 4TX | Terraced | £171,000 | |
| 21 Jul 1995 | 6 AL1 4TX | Terraced | £102,500 | |
| 20 Feb 2026 | 8 AL1 4TX | Terraced | £588,000 | |
| 8 Feb 2019 | 8 AL1 4TX | Terraced | £526,000 |
House prices and rents in St Albans
A typical home in St Albans cost £655,974 in August 2026, 3.2% more than a year before. That is 11% more than five years earlier and 19% more than ten years earlier.
| Home | Typical price, Aug 2026 |
|---|---|
| Detached | £1,274,817 |
| Semi-detached | £780,991 |
| Terraced | £585,030 |
| Flat or maisonette | £330,508 |
| Bought by a first-time buyer | £481,627 |
Private renters in St Albans paid £1,934 a month on average in September 2026, 2.7% more than a year before. That is 31% more than five years earlier.
| Home | Average rent a month, Sep 2026 |
|---|---|
| One bedroom | £1,272 |
| Two bedrooms | £1,635 |
| Three bedrooms | £2,023 |
| Four or more bedrooms | £2,907 |
Energy performance certificates
6 homes with a current certificate; median floor area 91 m². Most common: House, mid-terrace (5); House, end-terrace (1). Built: 1950-1966 (3); 1967-1975 (3). Tenure at assessment: owner-occupied (4); rented (private) (1).
Each home's certificates and sales (6 addresses)
Gas and electricity use
Homes with gas used 18,048 kWh of it on average in 2024, 33% more than the district's 13,577 kWh, and 4,121 kWh of electricity, 10% more than the district's 3,737 kWh. There are gas meters for about 100% of the homes.
| Postcode | Electricity meters | Typical electricity | Gas meters | Typical gas |
|---|---|---|---|---|
| AL1 4TX | 8 | 2,993 kWh | 8 | 13,757 kWh |
| AL1 4TU | 26 7 Economy 7 | 3,848 kWh | 27 | 21,897 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 AL1.
Council tax
What each band costs in St Albans in 2026-27: Band D £2,419 a year on average, including the police, fire and any county and parish charges.
| A | B | C | D | E | F | G | H |
|---|---|---|---|---|---|---|---|
| £1,613 | £1,882 | £2,150 | £2,419 | £2,957 | £3,494 | £4,032 | £4,838 |
Homes by band in the neighbourhood around this street: most are in band E (40% of about 530 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 direction (removing permitted development rights): none recorded, though not every council has published theirs.
- Tree preservation orders: none recorded, though not every council has published theirs.
- Green belt: no.
Brownfield land registered for housing within 1 km (0.6 miles)
- Jewson Depot: up to 37 homes, permissioned (830 m (0.5 miles))
Energy projects nearby
1 energy project near the street's postcodes.
| Project | Kind | Size | Stage | Distance |
|---|---|---|---|---|
| Coursers Farm AD Plant (Waste AD) Hertsmere 0/0262-12 | Anaerobic digestion | 3 MW | Operational Oct 2016 | 4.8 km (3 miles) |
Planned projects can change or not go ahead; search the planning authority's applications by the reference shown for the plans, conditions and any objections. Construction brings traffic for some months; once built, solar farms and batteries are usually quiet, while turbines and waste plants can be seen or heard further away.
Roadworks
No street works under way, planned or finished in the last three months on this street, in permits up to 31 October 2026.
Flood risk
Rivers, the sea or surface water: in this street's postcodes, 3 addresses are in areas at high risk, 0 at medium risk and 4 at low risk. Each address counts once, at the higher of its rivers-and-sea and surface-water risk.
Rivers and the sea alone: no home is in an area at risk.
High: 3.3% (1 in 30) or more chance of flooding a year. Medium: 1% to 3.3%. Low: 0.1% to 1%. Very low: under 0.1%. The rivers and sea figures allow for flood defences. 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.
| Postcode | Planning zone | Addresses at high / medium / low risk | Groundwater |
|---|---|---|---|
| AL1 4TX | not in 2 or 3 | 3 / 0 / 3 | unlikely |
| AL1 4TU | not in 2 or 3 | 0 / 0 / 1 | unlikely |
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.
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 1 to 3%: 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. 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 addresses are about 97 m above sea level.
Broadband
| Postcode | Superfast (30 Mbit/s+) | Ultrafast (300 Mbit/s+) | Gigabit | Below 10 Mbit/s |
|---|---|---|---|---|
| AL1 4TU | 100% | 100% | 100% | 0% |
| AL1 4TX | 100% | 100% | 100% | 0% |
Getting around
| Nearest | Distance | |
|---|---|---|
| Railway stations | St Albans City 6.7 million journeys in 2024–25 | 1.5 km (0.9 miles) |
| St Albans Abbey 149,000 journeys in 2024–25 | 2.7 km (1.7 miles) | |
| Park Street 22,000 journeys in 2024–25 | 4.1 km (2.6 miles) | |
| Bus stops | 9 stops within 400 m (0.2 miles), 26 within 800 m (0.5 miles); nearest Chestnut Drive Fleetville | 190 m |
| Bus or coach station | Parkhouse Bus Station Hatfield | 4.9 km (3 miles) |
| Car parks | Parking space on Elmshall Place, AL1 | 1.2 km (0.7 miles) |
| EV charging points | 3 within 1.6 km (1 mile); nearest MFG EV Power Charging Station | 730 m (0.5 miles) |
| Airport with scheduled flights | London Luton Airport LTN | 13.7 km (8.5 miles) |
Local services
| Nearest | Distance | |
|---|---|---|
| GP surgeries | Hatfield Road Surgery Good May 2018 | 1.6 km (1 mile) |
| Pharmacies | 6 pharmacies within 1.6 km (1 mile); nearest Morrisons Pharmacy | 670 m (0.4 miles) |
| NHS dentists | 4 practices within 1.6 km (1 mile); nearest Happy Family Dental | 750 m (0.5 miles) |
| Hospital | St. Albans City Hospital Requires improvement Jun 2020 | 2.4 km (1.5 miles) |
| Care homes | 6 homes within 1.6 km (1 mile); nearest Beau Sejour Care Services Good Dec 2019 | 690 m (0.4 miles) |
| Police station | London Colney Police Station | 4 km (2.5 miles) |
| Cash machines | St. Albans City Station, Station Way Cashzone | 1.3 km (0.8 miles) |
Parks and green space
| Nearest | Distance | |
|---|---|---|
| Park or garden | 4 within 800 m (0.5 miles); nearest Marshalswick Recreation Ground 4.8 ha | 250 m |
| Play area | 5 within 800 m (0.5 miles); nearest Unnamed 390 m² | 370 m |
| Playing field | 1 within 800 m (0.5 miles); nearest Unnamed 1.2 ha | 520 m (0.3 miles) |
| Allotments | Unnamed 1.0 ha | 1.2 km (0.7 miles) |
Within 800 m (0.5 miles): 4 parks and gardens, 7.7 hectares in all.
Landmarks
The nearest historic landmark is Iron Age territorial boundary known as Beech Bottom Dyke, a scheduled monument, 1.8 km (1.1 miles) north-west. 4 listed buildings are within 1 km (0.6 miles).
| Name | What it is | From the middle of the street |
|---|---|---|
| Iron Age territorial boundary known as Beech Bottom Dyke | Scheduled monument | 1.8 km (1.1 miles) north-west |
| Name | What it is | From the middle of the street |
|---|---|---|
| Wick Wood | Wood | 510 m (0.3 miles) north |
| Sky's Wood | Wood | 1 km (0.6 miles) north |
| Beech Bottom | Valley | 1.7 km (1.1 miles) north-west |
| Cell Barnes Pond | Lake or reservoir | 2.1 km (1.3 miles) south |
| Heron Island | Island | 2.9 km (1.8 miles) west |
| St Julian's Hill | Hill | 3.5 km (2.2 miles) south-west |
Air quality
| Pollutant | Here | UK limit | WHO guideline |
|---|---|---|---|
| Nitrogen dioxide (NO2) | 10.7 | 40 | 10 |
| Fine particles (PM2.5) | 7.6 | 20 | 5 |
| Particles (PM10) | 12.0 | 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 |
|---|---|---|
| 55 to 59 | 1 | 0 |
| Under 55 | 8 | 9 |
1 of the street's 9 addresses is 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 St Albans: see them on the St Albans page.
Nearest schools
| School | Phase | Ages | Distance | Inspection | Exam results |
|---|---|---|---|---|---|
| Verulam School | Secondary | 11–18 | 510 m (0.3 miles) | No published inspection | GCSE 2026 (provisional): Attainment 8 54.4 (52.5 in 2025 and 51.8 in 2024); 63.6% grade 5+ in English and maths A level 2025: average grade C+; 15.4% AAB or better; progress average |
| Fleetville Infant and Nursery School | Primary | 3–7 | 550 m (0.3 miles) | Outstanding (Dec 2023, overall grade under the previous framework) | None published |
| Oakwood Primary School | Primary | 4–11 | 650 m (0.4 miles) | Good (Jul 2024, overall grade under the previous framework) | 74% at the expected standard in reading, writing and maths, 11% at the higher standard (2025; 64% in 2024 and 74% in 2023) |
| Beaumont School | Secondary | 11–18 | 750 m (0.5 miles) | No overall grade (May 2025, graded inspection without an overall judgement): Quality of education: Outstanding; Behaviour and attitudes: Outstanding; Personal development: Outstanding; Leadership and management: Outstanding | GCSE 2026 (provisional): Attainment 8 63.0 (62.6 in 2025 and 59.0 in 2024); 76.1% grade 5+ in English and maths A level 2025: average grade B; 25.1% AAB or better; progress above average |
| Fleetville Junior School | Primary | 7–11 | 750 m (0.5 miles) | Good (Nov 2023, overall grade under the previous framework) | 78% at the expected standard in reading, writing and maths, 28% at the higher standard (2025; 78% in 2024 and 73% in 2023) |
| St John Fisher Catholic Primary School, a Voluntary Academy Roman Catholic | Primary | 4–11 | 1 km (0.6 miles) | No published inspection | 68% at the expected standard in reading, writing and maths, 13% at the higher standard (2025; 81% in 2024 and 81% in 2023) |
| St Alban & St Stephen Catholic Primary School & Nursery Roman Catholic | Primary | 3–11 | 1.1 km (0.7 miles) | Good (Nov 2023, overall grade under the previous framework) | None published |
| Camp Primary and Nursery School | Primary | 3–11 | 1.2 km (0.7 miles) | No published inspection | 71% at the expected standard in reading, writing and maths, 11% at the higher standard (2025; 48% in 2024 and 61% in 2023) |
| Skyswood Primary & Nursery School | Primary | 3–11 | 1.2 km (0.8 miles) | No overall grade (Feb 2025, graded inspection without an overall judgement): Quality of education: Outstanding; Behaviour and attitudes: Outstanding; Personal development: Outstanding; Leadership and management: Outstanding | 87% at the expected standard in reading, writing and maths, 37% at the higher standard (2025; 90% in 2024 and 84% in 2023) |
| Bernards Heath Infant and Nursery School | Primary | 3–7 | 1.3 km (0.8 miles) | Report card (Apr 2026): Curriculum and teaching: Expected standard; Achievement: Expected standard; Attendance and behaviour: Expected standard; Personal development and wellbeing: Strong standard; Inclusion: Strong standard; Leadership and governance: Expected standard; Early years: Expected standard; Safeguarding standards: Met | None published |
| Cunningham Hill Junior School | Primary | 7–11 | 1.5 km (0.9 miles) | Outstanding (Apr 2024, overall grade under the previous framework) | 87% at the expected standard in reading, writing and maths, 32% at the higher standard (2025; 88% in 2024 and 78% in 2023) |
| Cunningham Hill Infant School | Primary | 5–7 | 1.5 km (0.9 miles) | Outstanding (Jan 2024, overall grade under the previous framework) | None published |
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.
Nurseries and childcare
The ten nearest nurseries, pre-schools and clubs are all within 1.1 km (0.7 miles); the nearest is 410 m (0.3 miles) from the middle of the street.
| Provider | Kind | Places | Latest inspection | Distance |
|---|---|---|---|---|
| Mount Carmel Kindergarten AL4 0BX | Full day care | 62 | Outstanding (Sep 2024, overall grade under the previous framework) | 410 m (0.3 miles) |
| St Albans Steiner Kindergarten AL1 4LQ | Sessional day care | 20 | Good (Nov 2022, overall grade under the previous framework) | 580 m (0.4 miles) |
| Brain Up Abacus (St Albans) AL1 4LQ | Out-of-school day care (over fives) | Not inspected yet | 580 m (0.4 miles) | |
| Fleetville Community Playgroup AL1 4LQ | Sessional day care | 24 | Good (Oct 2023, overall grade under the previous framework) | 580 m (0.4 miles) |
| Jousters At Oakwood AL4 0XA | Out-of-school day care | 60 | Not inspected yet | 600 m (0.4 miles) |
| Club Excel @ Beaumont School AL4 0XB | Out-of-school day care | 240 | Mar 2026: Strong standard in 4 areas | 750 m (0.5 miles) |
| Grasshoppers Day Nursery (St Albans) AL1 4PL | Full day care | 64 | Outstanding (Feb 2024, overall grade under the previous framework) | 1 km (0.6 miles) |
| Busy Bees (Marshalswick) Ltd AL4 9QL | Full day care | 65 | Nov 2025: Expected standard in 2 areas, Needs attention in 4 | 1 km (0.6 miles) |
| Little Steps Day Nursery AL1 4EP | Full day care | 52 | Good (Mar 2024, overall grade under the previous framework) | 1.1 km (0.7 miles) |
| Re:Play @ St John Fisher AL4 9RW | Out-of-school day care | 40 | Not inspected yet | 1.1 km (0.7 miles) |
Ofsted also registers 841 childminders and 251 home childcarers (nannies) in Hertfordshire. It does not publish their addresses, so they cannot be shown here; the council's family information service lists those taking children.
Food hygiene ratings nearby
| Business | Type | Distance | Rating | Rated |
|---|---|---|---|---|
| St Albans URC Cosy Cafe & Luncheon Club AL1 4BH | Other catering premises | 360 m | 5 Very good | 11 Dec 2025 |
| Bean Central | Restaurant/Cafe/Canteen | 410 m (0.3 miles) | 5 Very good | 3 Sep 2025 |
| Central Drive Express AL4 0UX | Retailers - other | 420 m (0.3 miles) | 5 Very good | 27 Jan 2026 |
Crime within 250 m
| Category | Crimes |
|---|---|
| Other theft | 5 |
| Vehicle crime | 5 |
| Criminal damage and arson | 2 |
| Violence and sexual offences | 1 |
| Anti-social behaviour | 1 |
| Drugs | 1 |
Most of these are attached to: On or near St Johns Court (4); On or near Beechwood Avenue (3); On or near Woodstock Road North (2); On or near Gleave Close (2); On or near Garden Close (2).
Road safety
1 collision in which someone was hurt was reported on and around the street in 2021 to 2025: 0 fatal, 0 serious and 1 slight. Most were on roads with a 30 mph limit.
| Year | Collisions | Fatal or serious |
|---|---|---|
| 2021 | 0 | 0 |
| 2022 | 0 | 0 |
| 2023 | 0 | 0 |
| 2024 | 1 | 0 |
| 2025 | 0 | 0 |
| Date | Severity | Who was hurt | Road | Conditions |
|---|---|---|---|---|
| 13 May 2024 19:38 | Slight | 3 people | Minor road, 30 mph | Daylight |
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
No traffic count point is within 500 m (0.3 miles) of the street's postcodes. The Department for Transport counts every motorway and A road and only a sample of minor roads, so a quiet residential street usually has none.
People and work
Who lives here
| Around this street | England | |
|---|---|---|
| Median age | 46 | 40 |
| Children under 15 | 24% | 17% |
| Aged 65 and over | 22% | 18% |
Homes
| Around this street | England | |
|---|---|---|
| Owned (outright or with a mortgage) | 92% | 61% |
| Owned outright | 51% | 33% |
| Shared ownership | under 1% | 1% |
| Social rented | 0% | 17% |
| Private rented | 7% | 21% |
Work and commuting
| Around this street | England | |
|---|---|---|
| Adults (16 and over) in work | 63% | 57% |
| Unemployment (of those working or looking for work) | 3% | 6% |
| Retired (of adults) | 26% | 22% |
| Long-term sick or disabled (of adults) | under 1% | 4% |
| Work mainly from home (of those in work) | 65% | 32% |
| Travel to work by car or van | 22% | 48% |
| By train, Underground, metro or tram | 3% | 4% |
| By any public transport, including bus | 4% | 8% |
| On foot or by bicycle | 9% | 10% |
| Work within 10 km (6 miles) of home (of those who travel to work) | 62% | 65% |
| Work 30 km (19 miles) or more away | 10% | 8% |
Education and languages
| Around this street | England | |
|---|---|---|
| Degree or other higher qualification, Level 4+ (of adults) | 71% | 34% |
| No qualifications | 3% | 18% |
| Apprenticeship as highest qualification | 2% | 5% |
| Main language English (aged 3 and over) | 98% | 91% |
| Cannot speak English well or at all | 0% | 2% |
Deprivation
The neighbourhood around this street is in decile 10 of 10 on the English Indices of Deprivation 2025, where 1 is the most deprived tenth of England's 33,755 neighbourhoods and 10 the least.
What has changed
Nothing new since the change feed started on 30 October 2026. New sales and energy certificates, and hygiene ratings, school inspections and flood figures nearby, will be listed here as the sources update.
Postcodes on this street
Nearby streets
Salisbury Avenue · Gleave Close · Beechwood Avenue · Farm Road · Woodstock Road North · Chestnut Drive · Monks Horton Way · Hall Heath Close · Beaumont Avenue · Oakwood Drive · The Dell · Langford 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.