Collision diagrams made with My Traffic Sketch

Drafted with AI assistance; reviewed by the site operator on 2026-10-31. · How these pages are made

Each diagram on this page was drawn with this site's own editor, and the text under it describes only what the drawing shows. Plates and positions are fictional.

A diagram records positions and directions. It does not show speed, signal phase or who was at fault; those belong in the written narrative and the official report.

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Rear-end collision at the back of a line of stopped cars

A straight street runs east-west across the drawing: three lanes separated by dashed white lines, with no yellow center line. Solid white lines run along both edges. North is up. A dark stop line crosses all three lanes toward the east side of the drawing, with a "Stop line" label just below the road. The scale bar reads 4 m and each grid square is 2 m.

All three cars face east in the middle lane. V3 (LWN-635), a gray car, is at the front of the line, with its front just short of the stop line. V2 (CFR-248), a red car, is behind V3 with a clear gap between them. V2 and V3 have no arrows, which in this diagram means they are stopped. V1 (MZQ-791), a blue car, is behind V2 with its front against V2's rear; the white triangle that marks V1's front overlaps V2's rear. A straight arrow runs east along the middle lane behind V1 and ends just short of V1's rear.

X1, the impact point, sits at the north end of the contact between V1's front and V2's rear, over V2's rear corner and touching V1's front corner. V3 touches no other car and has no impact point, so the diagram records no impact on V3. The diagram shows the rear-end collision by placing V1 and V2 in the same lane, facing the same way, with the front of V1, the car with the arrow, against the rear of V2.

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Backing out of an angled parking stall: contact with a truck in the aisle

A parking lot with angled stalls: one row of stalls along the top edge, a double row of stalls back to back on a solid line across the middle, and one row along the bottom edge, with a drive aisle between each outer row and the double row. Each aisle has an outlined direction arrow pointing west. North is up, and the scale bar reads 4 m.

V1 (WDN-736) is in a stall on the south side of the upper aisle, lined up with the stall lines and about half out of the stall: its front points into the stall, toward the solid line, and its rear is out in the aisle. V1's arrow runs alongside V1's right side, from beside its front out into the aisle, and points out of the stall, the opposite way to V1's front. V2 (CVR-195), a truck, faces west in the northern part of the upper aisle, with a straight arrow behind it on its east side.

X1, the impact point, sits where V1's rear-right corner meets V2's left side, toward the rear of the truck, and it touches both vehicles. An arrow that points the way a vehicle's rear faces, not its front, shows that the vehicle was moving in reverse: V1's arrow points out of the stall while V1's front points in, so the diagram shows V1 backing out, not pulling in.

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Sideswipe during a lane change on a divided highway

A divided highway crosses the drawing: two carriageways of two lanes each, with a dashed white line between the lanes and a green median, edged in yellow, between the carriageways. North is up. The scale bar reads 4 m and each grid square is 2 m. Nothing is drawn on the northern carriageway.

Both cars face east in the southern carriageway. V2 (JLT-417) is in the left lane, next to the median, with a straight arrow behind it along that lane. V1 (KVM-563) is behind V2 and to its right, straddling the dashed lane line and turned slightly toward the median. V1's arrow runs along the middle of the right lane, then curves gently toward the lane line and ends just behind V1, lined up with its body.

X1, the impact point, sits where V1's front-left corner meets V2's right-rear corner, touching both cars. V1's angle across the lane line and its curved arrow are what show the lane change: together they trace V1's move out of the right lane toward V2's lane.

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Single-vehicle collision with a barrier arm at a lot exit

A parking lot fills the top of the drawing, with angled parking-space lines along its north side; north is up. A two-lane driveway runs south from the lot to a street along the bottom, which has a yellow dashed center line. A white dashed line divides the driveway into a west lane and an east lane, and grass lies on each side past a narrow light strip. A barrier arm, drawn as a thick dark line with a short, thicker block at its west end, crosses the west lane from the driveway's edge to the dashed line; a text box just west of it reads "Barrier arm". The scale bar reads 4 m and each grid square is 2 m.

V1 (FWN-385), a car, is in the west lane, the right-hand lane for a vehicle heading south out of the lot, and faces south toward the street. A straight arrow behind it runs from the lot down the lane and ends just behind V1. V1's front touches the barrier arm. No other vehicle is drawn.

X1, the impact point, sits on the barrier arm at V1's front, toward the car's east corner, touching both the car and the arm. With only one vehicle, the diagram still follows the usual pattern: the fixed object is drawn where it stands and named with a text label, the vehicle's arrow shows how it got there, and the impact point marks where the vehicle meets the object.

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Right-angle collision at a four-way intersection

A four-way intersection: a north-south road and an east-west road, each with two lanes divided by a dashed yellow center line, cross at right angles, with a crosswalk on each of the four sides. North is up; the scale bar reads 4 m and each grid square is 2 m.

V2 (LTJ-215), a red truck, faces east in the south half of the east-west road, inside the intersection between the west and east crosswalks, with its cab at the east end. A straight arrow behind it runs along the south half of the west arm, over the west crosswalk, and ends just behind V2. V1 (NRV-532), a blue car, faces north in the east half of the north-south road. Its front is just inside the intersection, and the car reaches back across the south crosswalk onto the south arm. A straight arrow behind it, in the same half of the south arm, points north and ends just behind V1.

X1, the impact point, sits where V1's front meets V2's right (south) side at the cab, and touches both vehicles. The diagram shows a right-angle collision: the two arrows are at right angles, and the front of one vehicle (V1) is drawn against the side of the other (V2), so the picture records which vehicle was hit in the side.

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Left-turn collision at a T-junction

A T-junction: a two-way main road with a dashed yellow center line runs east-west, and a side street joins it from the south, with a white crosswalk across the side street's mouth. North is up, as the compass shows. The scale bar reads 4 m and each grid square is 2 m.

V2 (PZN-650) faces east in the south half of the main road, its front just inside the junction, with a straight arrow behind it pointing east. V1 (FJT-317) is inside the junction with its front pointing north-west, lying across the south half of the main road: its front reaches just past the middle of the road, and its rear is just north of the east half of the side street. V1's trail starts in the east half of the side street, runs north, bends left as it approaches the crosswalk and ends in an arrowhead just behind V1's rear.

X1, the impact point, is where V2's front-left corner meets the front part of V1's left side; it touches both cars. The left turn shows in two places at once: V1 is drawn part-way through the turn, already facing north-west, and its trail bends left instead of running straight north.

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