Fears have been raised about the safety of the Thickthorn roundabout on the outskirts of Norwich following a serious crash yesterday morning.

An 18-year-old man from Swaffham suffered serious head injuries and a 60-year-old required hospital treatment following the rush-hour crash.

Reports of the crash online at www.eveningnews24.co.uk quickly attracted a string of comments as readers raised their concerns.

They included the length of the slip roads and lack of warning boards for traffic leaving the A47 for the A11, and the poor condition of the road markings on the roundabout itself.

The road was closed for several hours as police cleared the scene following the six-vehicle pile-up.

Officers are still seeking witnesses to the crash, in particular anyone who noted the driving of the silver Toyota Landcruiser, driven by the 60-year-old man, between the B1108 Watton Road junction and the Thickthorn roundabout prior to the accident.

User Whiley Boy said: 'Fingers crossed those involved are ok. That slip road is terrible at that time of the day for people speeding off the bypass into stationary traffic and braking harshly. They should install a speed camera to encourage slower driving near all slip roads.'

Daisy Roots agreed slip roads were a danger spot, saying: 'Slip roads off dual carriageways that are too short for the amount of slow-moving traffic or congestion, and the same speed limit on dual carriageways as on motorways without the same quality of warning signs, could also be contributing factor.'

Some commenters blamed the combination of drivers unfamiliar with the road layout, poor markings and a lack of signage.

Norwich Boy posted: 'The lane markings on the Thickthorn roundabout as you approach on the A11 from the south are not at all clear – leading to people not familiar with the intersection changing lanes at the last moment. It needs sorting out!'

Afoinecity added: 'The way the lanes merge coming back into Norwich catches too many people out. People jumping clear red lights all the time, and no cameras to catch them doing it, and blind slip roads with no warning signals.'