Free hours, tunnel vs bridge & traffic
The Dart Charge runs 6am to 10pm. Crossings between 10pm and 6am are free. Northbound goes through two tunnels, southbound takes the Queen Elizabeth II Bridge.
Dartford Crossing times: when you pay and when it's free
The charge applies 6am to 10pm, every day of the year including weekends and bank holidays. Crossings are free from 10pm to 6am, every night. Those are the only operating hours that matter for cost: cameras read your plate around the clock, but no charge is generated overnight. If you cross during charging hours you must pay by midnight the day after.
Dartford Crossing peak times: when to avoid it
In National Highways' counts for 1 September to 31 October 2025, the northbound tunnels were slowest at weekend midday (19 mph on Sundays 12pm to 1pm), then Friday 1pm to 7pm (24 mph) and weekday 4pm to 7pm (27 mph). The southbound bridge carried its heaviest flow on weekdays 6am to 7am, about 6,000 vehicles an hour. The quietest window is the free one: 10pm to 6am, around 1,300 vehicles an hour each way.
Charging hours
6am-10pm
every day, including weekends and bank holidays
Free window
10pm-6am
every night, no registration needed
Christmas Day
Free 10pm-6am
standard rate during the day, free overnight
Tunnel or bridge? Here's the rule.
The Dartford Crossing is one charge but two physical routes. Direction decides which one you take.
Kent to Essex: through the tunnels
Two bored tunnels, opened in 1963 and 1980. They sit beneath the Thames, one carrying two lanes. The two bores take different heights, which is the detail most height tables get wrong.
- Two tunnels, two lanes each
- West tunnel: maximum height 4.80m
- East tunnel: maximum height 5.03m, so 4.80m to 5.03m is east only
- Over 5.03m cannot use the tunnels, so cannot cross northbound here
- Hazardous load restrictions apply (escort vehicle)
- Northbound queues are typically longer than southbound
Essex to Kent: across the bridge
The Queen Elizabeth II Bridge, opened October 1991. A cable-stayed bridge, four lanes wide, visible from miles away on the A282 approach.
- Four lanes, southbound only
- No height limit in the regulations: 3.65m width, 27.4m length, 44,000kg
- Closes during severe wind (typically over 60mph)
- Free-flow at off-peak times
Height, width, length and weight limits are the prohibited dimensions in regulation 2(1) of the Dartford-Thurrock Crossing Regulations 1998, as substituted by regulation 4 of the Dartford-Thurrock Crossing (Amendment) Regulations 2014. Its explanatory note records that the west-tunnel height was "rounded down from 4.87 to 4.80 metres to facilitate the introduction of regulatory road signs". Checked 26 October 2026.
When to avoid it: traffic by hour, measured
National Highways runs traffic counters in both tunnels and on the southbound approach to the bridge. Across 1 September to 31 October 2025 they logged an average of 165,128 vehicles a weekday in the two directions together, and 149,012 on a weekend day. Speed is the congestion signal, and only the tunnel counters record it, so the northbound table shows speed and the southbound table shows volume.
Northbound (tunnels): average speed, mph
| When | Mon-Thu | Fri | Sat | Sun |
|---|---|---|---|---|
| 6am-7am | 34 | 36 | 41 | 42 |
| 7am-10am | 32 | 34 | 37 | 40 |
| 10am-1pm | 30 | 25 | 23 | 25 |
| 1pm-4pm | 29 | 24 | 23 | 21 |
| 4pm-7pm | 27 | 24 | 29 | 23 |
| 7pm-10pm | 40 | 34 | 39 | 34 |
| 10pm-6am (free) | 39 | 39 | 37 | 37 |
Southbound (QE2 Bridge): vehicles an hour
| When | Mon-Thu | Fri | Sat | Sun |
|---|---|---|---|---|
| 6am-7am | 6,051 | 5,811 | 2,422 | 1,444 |
| 7am-10am | 5,154 | 4,734 | 3,718 | 2,726 |
| 10am-1pm | 4,448 | 5,032 | 5,584 | 4,919 |
| 1pm-4pm | 4,948 | 5,634 | 5,052 | 5,217 |
| 4pm-7pm | 5,246 | 5,566 | 4,841 | 5,200 |
| 7pm-10pm | 2,538 | 3,188 | 2,978 | 3,265 |
| 10pm-6am (free) | 1,306 | 1,459 | 1,254 | 1,056 |
Every hour of the week, northbound speed
Live traffic
For real-time conditions, these are the most reliable sources, in order. None of them are run by Dart Charge.
- Google Maps / Waze: community-fed, fastest to spot incidents.
- RAC traffic news: incident details for the M25 region.
- National Highways customer information service: official planned closures and diversions.
- @HighwaysSEAST on X for live alerts on the eastern section of the M25.
Times & traffic questions
What are the Dartford Crossing operating and charging hours?+
The Dart Charge applies from 6am to 10pm, every day of the year including weekends and bank holidays. There are no separate weekday or Sunday charging times: the 6am to 10pm window is the same all week. The crossing itself stays open 24 hours; only the charge switches off overnight.
When is the Dartford Crossing free?+
Every night between 10pm and 6am, every day of the year including weekends and bank holidays. Outside that window, from 6am to 10pm, the charge always applies. ANPR cameras still read your plate overnight, but no charge is generated.
What times should I avoid the Dartford Crossing today?+
Going by National Highways' own traffic counters for September and October 2025, the northbound tunnels were slowest at weekend midday (an average of 19 mph on Sundays from 12pm to 1pm and 20 mph on Saturdays), then on Friday afternoons (24 mph from 1pm to 7pm) and weekday evenings (27 mph from 4pm to 7pm, Monday to Thursday). Southbound over the QE2 Bridge, the heaviest flow of the week was weekdays 6am to 7am, about 6,000 vehicles an hour. The quietest time is the free 10pm to 6am window: around 1,300 vehicles an hour each way and 39 mph through the tunnels on weekday nights. Those are averages; check live traffic before you set off.
Which way goes through the tunnel and which way over the QE2 Bridge?+
Northbound, from Kent to Essex, goes through the two bored tunnels. Southbound, from Essex to Kent, crosses the Queen Elizabeth II Bridge. It is one charge whichever route you take; direction decides which structure you use.
What is the height limit for the Dartford Crossing tunnels?+
The two bores have different limits. The Dartford-Thurrock Crossing Regulations 1998, as amended in 2014, prohibit vehicles over 4.80 metres overall height in the west tunnel and over 5.03 metres in the east. So anything between those two figures is east tunnel only, and anything over 5.03m cannot use the tunnels at all. The tunnels carry the northbound traffic, so that is a northbound constraint: the regulations set no height limit for the southbound QE2 Bridge, only a 3.65m width, a 27.4m length and a 44,000kg weight limit. The west-tunnel figure is 4.80m rather than 4.87m because the regulations rounded it down for the road signs.
Is the Dartford Crossing free on Christmas Day or bank holidays?+
No. The charge applies on Christmas Day and every bank holiday during the standard 6am to 10pm hours, despite a persistent rumour to the contrary. Like any other day, crossings are only free overnight between 10pm and 6am.