A-road
A121 traffic and collisions
The A121 is an A-road of 10.4 miles, from Redbridge to Hertfordshire. This page covers its traffic at 11 DfT count points since 2000 and the collisions police recorded on it.
- Traffic in 2025 63m vehicle miles
- Average daily traffic 16,462 vehicles a day, both directions
- Busiest section 25,167 B176 to A10
- HGV share 3.8% of vehicle miles
- Traffic since 2019 −4.1% same count points
- Collisions, 2021 to 2025 190 60.6 per 100m vehicle miles
How busy is the A121?
On an average day in 2025, 16,462 vehicles passed each point on the A121, counting both directions. The busiest section is B176 to A10 (Hertfordshire), with 25,167 a day; the quietest listed is A104 to A1168, with 10,425.
Busiest sections, 2025
B176 to A10 carries 1.5 times the road’s average flow.
| Section | Vehicles a day |
|---|---|
| B176 to A10 Hertfordshire · 0.5 mi · HGVs 3.5% | 25,167 |
| A104 to A121 Honey Lane roundabout Essex · 1.3 mi · HGVs 2.4% | 22,077 |
| Baldwin's Hill to A104 Essex · 0.9 mi · HGVs 1.7% | 17,145 |
| A112 to A121 / A1010 Essex, Hertfordshire · 2.2 mi · HGVs 5.8% | 16,664 |
| A121 Honey Lane roundabout to A112 Essex · 1.4 mi · HGVs 9.3% | 14,530 |
| A104 to A1168 Redbridge, Essex · 3.0 mi · HGVs 0.9% | 10,425 |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
Route
Redbridge to Hertfordshire · 10.4 miles
A121 traffic and collisions by section
8 sections between junctions, in route order. Each is the average of its DfT count points, weighted by length. 1 short link roads and spurs (0.3 miles) count in the road’s totals but are not listed.
Sections Tap a column heading to sort
| # | |||
|---|---|---|---|
| 1 | A104 to A1168Redbridge, Essex | 10,425 | 50 |
| 2 | A1168 to Baldwin's HillEssex | 18,173 | 5 |
| 3 | Baldwin's Hill to A104Essex | 17,145 | 11 |
| 4 | A104 to A121 Honey Lane roundaboutEssex | 22,077 | 31 |
| 5 | A121 Honey Lane roundabout to A112Essex | 14,530 | 9 |
| 6 | A112 to A121 / A1010Essex, Hertfordshire | 16,664 | 45 |
| 7 | A1010 to B176Hertfordshire | 33,186 | 12 |
| 8 | B176 to A10Hertfordshire | 25,167 | 24 |
Vehicles a day is the average daily flow in 2025. “Since 2019” compares the same count points. Collisions are those with the A121 as the first road, placed on the nearest section by their recorded position; rates (per 100 million vehicle miles) are shown for sections of half a mile or more with 10 or more.
A121 traffic by vehicle type
Cars and taxis make up 77.5% of the vehicle miles on the A121. HGVs account for 3.8%, rising to 9.3% on A121 Honey Lane roundabout to A112.
Vehicle mix, 2025
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
HGV share of traffic
| Year | HGV share |
|---|---|
| 2000 | 3.4% |
| 2001 | 3.3% |
| 2002 | 3.4% |
| 2003 | 3.8% |
| 2004 | 4.0% |
| 2005 | 3.9% |
| 2006 | 3.9% |
| 2007 | 3.9% |
| 2008 | 3.9% |
| 2009 | 3.8% |
| 2010 | 3.9% |
| 2011 | 4.0% |
| 2012 | 4.0% |
| 2013 | 4.1% |
| 2014 | 4.0% |
| 2015 | 4.0% |
| 2016 | 3.9% |
| 2017 | 4.2% |
| 2018 | 4.1% |
| 2019 | 4.2% |
| 2020 | 4.5% |
| 2021 | 4.0% |
| 2022 | 4.2% |
| 2023 | 4.0% |
| 2024 | 4.0% |
| 2025 | 3.8% |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
A121 traffic trend
Traffic on the A121 came to 62.5 million vehicle miles in 2025. At the count points present in both years, it is down 4.1% on 2019, before the pandemic, and down 9.1% on 2015.
Vehicle miles a year
Like for like, traffic is up 0.9% on 2000.
| Year | Vehicle miles |
|---|---|
| 2000 | 60m |
| 2001 | 60m |
| 2002 | 61m |
| 2003 | 61m |
| 2004 | 63m |
| 2005 | 62m |
| 2006 | 63m |
| 2007 | 61m |
| 2008 | 64m |
| 2009 | 61m |
| 2010 | 60m |
| 2011 | 60m |
| 2012 | 60m |
| 2013 | 63m |
| 2014 | 65m |
| 2015 | 66m |
| 2016 | 66m |
| 2017 | 63m |
| 2018 | 63m |
| 2019 | 65m |
| 2020 | 52m |
| 2021 | 61m |
| 2022 | 63m |
| 2023 | 64m |
| 2024 | 63m |
| 2025 | 63m |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
Average daily flow
| Year | Vehicles a day |
|---|---|
| 2000 | 16,135 |
| 2001 | 16,283 |
| 2002 | 16,507 |
| 2003 | 16,594 |
| 2004 | 16,946 |
| 2005 | 16,672 |
| 2006 | 17,090 |
| 2007 | 16,573 |
| 2008 | 17,219 |
| 2009 | 16,536 |
| 2010 | 16,275 |
| 2011 | 16,328 |
| 2012 | 16,231 |
| 2013 | 17,041 |
| 2014 | 17,501 |
| 2015 | 18,000 |
| 2016 | 18,013 |
| 2017 | 17,149 |
| 2018 | 17,195 |
| 2019 | 17,160 |
| 2020 | 13,700 |
| 2021 | 15,959 |
| 2022 | 16,616 |
| 2023 | 16,932 |
| 2024 | 16,673 |
| 2025 | 16,462 |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
The chart counts the whole road as it was each year, so new or renumbered stretches move it. The percentage changes compare only count points present in both years. In 2025, 2 of the 11 count points were counted; DfT estimated the rest from earlier counts and local trends.
A121 collisions
Police recorded 190 collisions with the A121 as the first road from 2021 to 2025, 49 of them fatal or serious, including 4 fatal. That is 60.6 per 100 million vehicle miles, higher than the 31.5 for all A-roads in Great Britain. On average there were 3.7 a year for each mile of road.
Reported collisions by year
Down 5.4% from 2021 to 2025.
| Year | Slight | Fatal or serious |
|---|---|---|
| 2021 | 26 | 11 |
| 2022 | 31 | 10 |
| 2023 | 28 | 5 |
| 2024 | 34 | 10 |
| 2025 | 22 | 13 |
Source:DfT STATS19,UK Motoring analysis 2021 to 2025 Updated
Sections with the highest collision rates
Per 100 million vehicle miles, 2021 to 2025. Sections of half a mile or more with 10 or more collisions.
| Section | Per 100m vehicle miles |
|---|---|
| B176 to A10 Hertfordshire · 24 collisions | 109.8 |
| A104 to A1168 Redbridge, Essex · 50 collisions | 83.1 |
| A112 to A121 / A1010 Essex, Hertfordshire · 45 collisions | 69.1 |
| A104 to A121 Honey Lane roundabout Essex · 31 collisions | 59.2 |
| Baldwin's Hill to A104 Essex · 11 collisions | 40.7 |
Source:DfT STATS19,UK Motoring analysis 2021 to 2025 Updated
A further 30 collisions were recorded at junctions where the A121 was the second road; they are not in the figures above. Fatal or serious uses DfT’s adjusted serious figures. 98.4% of the collisions could be placed on a section. How we count collisions
Council areas on the A121
In route order. Each is the highway authority DfT files the count points under.
- Redbridge
- Essex
- Hertfordshire
Data sources and methodology
| Figures | Source | Period | Records | Updated |
|---|---|---|---|---|
| Traffic counts and vehicle mix | Road traffic statistics (AADF by count point) Department for Transport Derived statistics UK Motoring | 2000 to 2025 | 11 count points in 2025 | 15 September 2026 |
| Reported collisions | Road safety open data (STATS19) Department for Transport Derived statistics UK Motoring | 2021 to 2025 | 190 reported collisions | 15 September 2026 |
- Annual average daily flow (AADF) is the average number of vehicles passing a point on a typical day of the year, both directions combined.
- Vehicle miles are AADF multiplied by link length and 365, summed over every count point link on the road.
- Sections join count point links between junctions, using the link lines in DfT’s major road database.
- STATS19 covers personal injury collisions reported to the police. Damage-only collisions are not included, and not every injury collision is reported.
- Serious and slight figures are DfT’s adjusted estimates, which allow for police forces moving to injury-based reporting.
- Counts of one or two collisions below Great Britain level are shown as “fewer than 3”.
Contains public sector information licensed under the Open Government Licence v3.0.