Never let in
Let one in
Both maps get exactly the same cars, arriving at the same moments and heading to the same exits. The only difference is the drivers on the main road.
Time lost adds up every driver's delay compared with an empty road, including people still stuck on the map and people still waiting to get onto it. Both maps get the same cars, so this is the fairest single comparison. The averages on the maps only cover trips that have finished, so they can look fine while people are stuck.
Unluckiest is the time lost by the unluckiest 1 in 20 drivers: line everyone up from least to most time lost, including people still stuck, and take the one 95% of the way along. It shows how bad it gets for the people who come off worst.
On each map, Through is drivers who only use the main road and Giving way is drivers who have to pull out, merge in or turn across traffic at some point. Each shows time lost compared with an empty road: the average over the last minute, and the worst, which is the slowest 5% or the longest anyone is still stuck waiting, whichever is bigger.
Never let in: anyone pulling out or turning right across traffic waits for a natural gap.
Let one in: when someone is waiting, the next main-road driver holds back to let them go, with the chance on the slider.
Shopping centre: a two-way main road with a supermarket set back behind two junctions. Eastbound shoppers turn left in at the west junction, go round the outside of the car park and come out at the east junction. Westbound shoppers turn right across the eastbound lane at the east junction, go round the inside and come out at the west junction. Coming out, they can turn left, or right across the eastbound lane. There are no right-turn pockets, so a car waiting to turn right holds up everyone behind it, and when the car park is full the queue backs out onto the main road.
City grid: one-way streets, where the cross streets give way to the avenues. A queue backing through a junction blocks the street crossing it. Drive-thru: the window serves one car at a time, so the queue can reach the main road. Housing estate: one way in and out, so morning and evening everyone turns across the same lane. Motorway junction: an off-slip queue at the lights can back up past the on-slip, which the local road needs to empty into.
Road with loop: a side road leaves the main road, runs back past the village and rejoins the main road at a give-way. Some drivers pop into the shop and come straight back out, so they go all the way round. If the side road fills back to where it leaves, cars waiting to turn off block the main road, and the main road is what the side road is waiting on.
Irish rules: everyone drives on the left, and turning right means crossing the oncoming lane. 💗 is someone holding back, 👋 is the thank-you, 💢 is a car that has been stuck a while. Bubbles at the edge count cars still waiting to get onto the map. 🚦 adds traffic lights where roads leave the map, standing in for a busy town beyond.