Side-Impact (T-Bone) Collision: Who Is At Fault?

Who is usually at fault?

In a side-impact collision, the driver who failed to give way is usually at fault. At a junction, that is the driver who pulled out into the path of a vehicle on the main road. At a roundabout, it is the driver who entered without giving way to traffic already on it. During a lane change, it is the driver who moved without checking the target lane was clear.

The physical damage often helps establish what happened: the position and angle of the impact on each vehicle tends to reflect the direction each driver was travelling.

The starting point

In most side-impact collisions, fault falls on the driver who failed to give way. Evidence (particularly dash cam footage} often determines whether that position holds.

When it isn’t that simple

Fault is not always clear-cut in side-impact cases:

Both drivers claim to have had right of way, and there is no independent evidence
Road markings or signage are absent, unclear or disputed
The incident occurred during a lane change on a multi-lane road where both cars were moving
One driver had a green light at a junction and the other disputes the signal state

Junctions, roundabouts and lane changes

At a junction

A driver emerging from a minor road or side street must give way to traffic on the main road. If they pull out and are struck by a vehicle that had right of way, fault ordinarily falls on them.

On a roundabout

Traffic already on a roundabout has priority over traffic entering it. A driver who enters without waiting for a clear gap is ordinarily at fault for any collision that results.

Changing lanes

A driver changing lanes must check the target lane is clear before moving into it. A collision caused by a lane change whether on a motorway, dual carriageway or multi-lane urban road, will generally be treated as the fault of the driver who moved.

What evidence helps

Fault in side-impact cases is frequently disputed, which makes evidence particularly important:

Dash cam footage: dash cams and non-fault accidents
Photographs of both vehicles and the road layout
Witness contact details
CCTV from nearby junctions or businesses

What to do next

If you were struck in a side-impact collision and the fault position supports a non-fault claim, call us. We will assess the situation and tell you whether we can take it on.

What to do after a car accident · Non-fault accident: what to do and who pays.

How it costs you nothing

We recover our costs from the at-fault driver’s insurer, which is why the claim costs you nothing. That applies where another driver was at fault and holds valid motor insurance, which covers most road traffic accidents. If they refuse to accept fault, we argue it for you. We check yours on the first call and tell you where you stand before you sign anything.

Frequently asked questions

Who is at fault in a T-bone collision?

Usually the driver who failed to give way. At a junction, that is the driver who pulled out into the path of an oncoming vehicle. At a roundabout, it is the driver who entered without waiting for a clear gap. The physical damage and any available footage generally support or complicate that starting position.

What if we both say we had right of way?

Where both drivers dispute fault and there is no independent evidence, no witnesses, no dash cam footage, no CCTV, the position can be genuinely unclear. In those cases, insurers often negotiate a split-liability settlement. We will tell you if that applies to your situation on the first call.

Does a dash cam help?

Yes. Dash cam footage is often the most useful evidence in side-impact cases, where the physical damage alone does not always resolve a right-of-way dispute. If you have footage, secure it before it is overwritten and do not share it without speaking to us first.

Start your claimStart your claim Call 0208 988 9508Call now

Side-impact collision: who is at fault?

A side-impact collision typically happens at a junction, on a roundabout, or during a lane change. Fault depends on who had right of way and what the evidence shows.