J4 for A408
J4B for M25
M4 Greater London - Severe delays and one lane closed on M4 westbound between J4, A408 (Heathrow Spur) and J4b M25, because of an accident involving two cars and a motorcycle and an oil spillage. Tailbacks for 11 miles. Travel time is over 60 minutes. Congestion on A4 to the Hammersmith Flyover junction.