The traffic black spots

To learn more about exactly where and when traffic snarl-ups are likely to occur, we've prepared a list of ten of the most notorious trouble-spots.

Trafficmaster helped us to say when congestion is likely to occur this summer, so plan these into your itinerary and avoid them if possible, or, where there are suggested alternatives, use these instead.

You can see where the jams below occur by clicking here (opens a new window).

Scotland
Road: M8, junctions 2-6, junctions 9-22
Busiest day/time: Friday 5-7pm
Bank holiday peak: Friday 5-7pm, Sunday/Monday 4-6pm
Expected peak delays: More than an hour
Possible alternative routes: A80, M80, M9
Trafficmaster says: It's full of commuters, and holidaymakers add to the problem. The longer M80/M9 route is sometimes quicker. Avoid the Central Glasgow section unless you're heading to the city centre.

Road: M90, junctions 1-4 (Forth Bridge)
Busiest day/time: Friday 5-7pm
Bank holiday peak: Friday 5-7pm, Saturday 10am-12pm, Sunday/ Monday 4-6pm
Expected peak delays: 30 minutes
Possible alternative routes: A876 (Kincardine Bridge)
Trafficmaster says: Traffic often backs up, so an alternative crossing may be easier.

Wales
Road: M4, junctions 23-34
Busiest day/time: Friday 5-7pm
Bank holiday peak: Friday 5-7pm, Saturday 10am-12pm, Sunday/ Monday 4-6pm
Expected peak delays: 30-45 minutes
Possible alternative routes: None
Trafficmaster says: Busiest at holiday times, this is the main England-Wales route and links to the M5. Any bad weather affects the Severn crossings.

England
Road: M6, junctions 1-15
Busiest day/time: Friday 5-7pm
Bank holiday peak: Friday 5-7pm, Sunday/Monday 4-6pm
Expected peak delays: More than an hour
Possible alternative routes: The M6 toll
Trafficmaster says: The fourth-most congested area in the country. The M6 Toll - at 4 a car - is worth the price at peak times.

Road: M6, junctions 11-35
Busiest day/time: Friday 5-7pm
Bank holiday peak: Friday 5-7pm, Saturday 10am-12pm, Sunday/Monday 4-6pm
Expected peak delays: More than an hour
Possible alternative routes: M1, M62
Trafficmaster says: A big holiday route. Avoid it at peak times.

Road: M25, junctions 9-28
Busiest day/time: Friday 4-8pm
Bank holiday peak: Friday 2-8pm, Sunday/Monday 4-7pm
Expected peak delays: Up to an hour past Heathrow Airport
Possible alternative routes: None to get around London; North Circular and South Circular suffer heavy congestion.
Trafficmaster says: Roadworks at junction 25 add to congestion, so plan your journey around rush hours.

Road: M1, junctions 6A-12
Busiest day/time: Friday 4-7pm
Bank holiday peak: Friday 4-7pm, Sunday/Monday 5-7pm
Expected peak delays: Up to an hour to get from junctions 8-10
Possible alternative routes: A1 or M40
Trafficmaster says: Our worst congestion hotspot. Major roadworks both ways from junctions 8-10 mean peak-time tailbacks daily. M40 is nearly always quicker.

Road: M1, junctions 21-30
Busiest day/time: Friday 4-7pm
Bank holiday peak: Friday 4-7pm, Sunday/Monday 5-7pm
Expected peak delays: Up to 45 minutes past East Midlands Airport
Possible alternative routes: A1
Trafficmaster says: Worse northbound on Fridays, with East Midlands airport traffic on top of commuters. There are also now major roadworks near Rotherham.

Road: M5, junctions 15-22
Busiest day/time: Friday 4-7pm
Bank holiday peak: Friday 4-7pm, Saturday 9-11am, Sunday/Monday 5-7pm
Expected peak delays: More than an hour between Bristol and Weston super Mare
Possible alternative routes: A303
Trafficmaster says: Caravans and uphill sections slow the traffic. The A303 can be better from the east and Midlands.

Road: M4, junctions 8-18
Busiest day/time: Friday 4-7pm
Bank holiday peak: Friday 4-7pm, Saturday 9-11am, Sunday/Monday 5-7pm
Expected peak delays: Up to 45 minutes
Possible alternative routes: M3, A303
Trafficmaster says: Holiday traffic mixes with local traffic at Maidenhead, Reading and Swindon.