A-road
A602 traffic and collisions
The A602 is an A-road of 18.1 miles, in Hertfordshire. This page covers its traffic at 17 DfT count points since 2000 and the collisions police recorded on it.
- Traffic in 2025 170m vehicle miles
- Average daily traffic 25,796 vehicles a day, both directions
- Busiest section 36,908 Coreys Mill Lane to A1(M)
- HGV share 2.3% of vehicle miles
- Traffic since 2019 +1.2% same count points
- Collisions, 2021 to 2025 210 27.3 per 100m vehicle miles
How busy is the A602?
On an average day in 2025, 25,796 vehicles passed each point on the A602, counting both directions. The busiest section is Coreys Mill Lane to A1(M) (Hertfordshire), with 36,908 a day; the quietest listed is A119 to Hertford Rd, Stevenage, with 19,611.
Busiest sections, 2025
Coreys Mill Lane to A1(M) carries 1.4 times the road’s average flow.
| Section | Vehicles a day |
|---|---|
| Coreys Mill Lane to A1(M) Hertfordshire · 0.5 mi · HGVs 1.3% | 36,908 |
| Whitehill Rd to B656 Hertfordshire · 0.6 mi · HGVs 2.7% | 34,044 |
| A1(M) to Whitehill Rd, Hitchin Hertfordshire · 2.3 mi · HGVs 2.7% | 32,117 |
| A1070 to A1155 Hertfordshire · 0.6 mi · HGVs 0.3% | 29,180 |
| B656 to A505 Hertfordshire · 0.7 mi · HGVs 2.7% | 28,161 |
| Hertford Rd to B197 Hertfordshire · 2.3 mi · HGVs 2.0% | 27,256 |
| B197 to A1155 Hertfordshire · 0.7 mi · HGVs 0.5% | 25,172 |
| A10 to A119 Hertfordshire · 4.2 mi · HGVs 3.2% | 21,955 |
| A1155 to A602 split Hertfordshire · 0.8 mi · HGVs 0.6% | 21,169 |
| A119 to Hertford Rd, Stevenage Hertfordshire · 3.4 mi · HGVs 3.1% | 19,611 |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
Route
In Hertfordshire · 18.1 miles
A602 traffic and collisions by section
14 sections between junctions, in route order. Each is the average of its DfT count points, weighted by length. 3 short link roads and spurs (1.0 miles) count in the road’s totals but are not listed.
Sections Tap a column heading to sort
| # | |||
|---|---|---|---|
| 1 | A10 to A119Hertfordshire | 21,955 | 26 |
| 2 | A119 to Hertford Rd, StevenageHertfordshire | 19,611 | 21 |
| 3 | Hertford Rd to B197Hertfordshire | 27,256 | 18 |
| 4 | B197 to A1155Hertfordshire | 25,172 | 10 |
| 5 | A1155 to A1070Hertfordshire | 19,373 | 9 |
| 6 | A1070 to A1155Hertfordshire | 29,180 | 9 |
| 7 | A1155 to A602 splitHertfordshire | 21,169 | 14 |
| 8 | A602 split to A602 mergeHertfordshire | 15,941 | 5 |
| 9 | A602 split to A1072Hertfordshire | 17,858 | 8 |
| 10 | A1072 to Coreys Mill LaneHertfordshire | 40,558 | 8 |
| 11 | Coreys Mill Lane to A1(M)Hertfordshire | 36,908 | 16 |
| 12 | A1(M) to Whitehill Rd, HitchinHertfordshire | 32,117 | 28 |
| 13 | Whitehill Rd to B656Hertfordshire | 34,044 | 10 |
| 14 | B656 to A505Hertfordshire | 28,161 | 16 |
Vehicles a day is the average daily flow in 2025. “Since 2019” compares the same count points. Collisions are those with the A602 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.
A602 traffic by vehicle type
Cars and taxis make up 81.6% of the vehicle miles on the A602. HGVs account for 2.3%.
Vehicle mix, 2025
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
HGV share of traffic
| Year | HGV share |
|---|---|
| 2000 | 3.5% |
| 2001 | 3.5% |
| 2002 | 3.8% |
| 2003 | 4.3% |
| 2004 | 4.0% |
| 2005 | 3.7% |
| 2006 | 3.9% |
| 2007 | 4.1% |
| 2008 | 3.8% |
| 2009 | 3.5% |
| 2010 | 3.2% |
| 2011 | 3.2% |
| 2012 | 3.2% |
| 2013 | 3.2% |
| 2014 | 3.1% |
| 2015 | 3.0% |
| 2016 | 3.1% |
| 2017 | 3.1% |
| 2018 | 2.8% |
| 2019 | 2.5% |
| 2020 | 3.0% |
| 2021 | 2.6% |
| 2022 | 2.5% |
| 2023 | 2.4% |
| 2024 | 2.4% |
| 2025 | 2.3% |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
A602 traffic trend
Traffic on the A602 came to 170 million vehicle miles in 2025. At the count points present in both years, it is up 1.2% on 2019, before the pandemic, and up 1.5% on 2015.
Vehicle miles a year
Like for like, traffic is up 2.6% on 2000.
| Year | Vehicle miles |
|---|---|
| 2000 | 137m |
| 2001 | 140m |
| 2002 | 142m |
| 2003 | 144m |
| 2004 | 143m |
| 2005 | 144m |
| 2006 | 151m |
| 2007 | 147m |
| 2008 | 143m |
| 2009 | 141m |
| 2010 | 137m |
| 2011 | 142m |
| 2012 | 138m |
| 2013 | 143m |
| 2014 | 149m |
| 2015 | 152m |
| 2016 | 156m |
| 2017 | 151m |
| 2018 | 152m |
| 2019 | 157m |
| 2020 | 119m |
| 2021 | 134m |
| 2022 | 147m |
| 2023 | 154m |
| 2024 | 166m |
| 2025 | 170m |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
Average daily flow
| Year | Vehicles a day |
|---|---|
| 2000 | 22,762 |
| 2001 | 23,174 |
| 2002 | 23,494 |
| 2003 | 23,877 |
| 2004 | 23,735 |
| 2005 | 23,847 |
| 2006 | 25,000 |
| 2007 | 24,403 |
| 2008 | 23,751 |
| 2009 | 23,409 |
| 2010 | 22,758 |
| 2011 | 22,960 |
| 2012 | 22,400 |
| 2013 | 23,116 |
| 2014 | 24,113 |
| 2015 | 24,666 |
| 2016 | 25,254 |
| 2017 | 24,526 |
| 2018 | 23,386 |
| 2019 | 24,163 |
| 2020 | 18,379 |
| 2021 | 20,581 |
| 2022 | 22,581 |
| 2023 | 23,634 |
| 2024 | 25,478 |
| 2025 | 25,796 |
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 (64.1% of today’s road for 2019). In 2025, 5 of the 17 count points were counted; DfT estimated the rest from earlier counts and local trends.
A602 collisions
Police recorded 210 collisions with the A602 as the first road from 2021 to 2025, 38 of them fatal or serious, including 5 fatal. That is 27.3 per 100 million vehicle miles, lower than the 31.5 for all A-roads in Great Britain. On average there were 2.3 a year for each mile of road.
Reported collisions by year
Up 56.3% from 2021 to 2025.
| Year | Slight | Fatal or serious |
|---|---|---|
| 2021 | 27 | 5 |
| 2022 | 41 | 6 |
| 2023 | 34 | 5 |
| 2024 | 33 | 9 |
| 2025 | 37 | 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 |
|---|---|
| Hertford Rd to B197 Hertfordshire · 18 collisions | 78.7 |
| A10 to A119 Hertfordshire · 26 collisions | 77.3 |
| Coreys Mill Lane to A1(M) Hertfordshire · 16 collisions | 50.2 |
| B656 to A505 Hertfordshire · 16 collisions | 48.8 |
| A1155 to A602 split Hertfordshire · 14 collisions | 48.4 |
| B197 to A1155 Hertfordshire · 10 collisions | 33.4 |
| Whitehill Rd to B656 Hertfordshire · 10 collisions | 27.5 |
| A1(M) to Whitehill Rd, Hitchin Hertfordshire · 28 collisions | 21.3 |
Source:DfT STATS19,UK Motoring analysis 2021 to 2025 Updated
A further 54 collisions were recorded at junctions where the A602 was the second road; they are not in the figures above. Fatal or serious uses DfT’s adjusted serious figures. 94.3% of the collisions could be placed on a section. How we count collisions
Council areas on the A602
In route order. Each is the highway authority DfT files the count points under.
- 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 | 17 count points in 2025 | 15 September 2026 |
| Reported collisions | Road safety open data (STATS19) Department for Transport Derived statistics UK Motoring | 2021 to 2025 | 210 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.