The steps below will enable you to calculate how to use our London primary school dashboard to estimate how many car trips are created by the primary school run. This can be helpful to focus parents, schools and local authorities on the need to reduce these journeys.
Estimating school run car trips
STEP 1 - Find out how many primary pupils are driven to school
Use our primary school travel dashboard to estimate how many pupils are driven to school.
Go to the OVERVIEW section of our London primary school dashboard.
Use the filters to select the borough, ward, school type or school that you want to focus on.
The modelled numbers of pupils driven to school for that selection will display. These numbers were modelled using the actual distances that pupils are travelling to school and combining them with the London average driving rates for those distances. You can find out more about our methodology here.
In the example below, we have the whole of London selected, which shows that there are 200,000 (or exactly 196,029) pupils driven to primary schools in London.
STEP 2 - Convert that number into the number of car trips this generates per day
To estimate the number of car trips this creates, we have to consider that there will be siblings in cars, so not every pupil driven equals one car.
Additionally, we should consider that there could be up to 4 car trips per day generated by the school run. In the morning a pupil can be driven to school, dropped off and then the parent can drive home again ( two car trips). In the afternoon, the parent can drive to school, pick up the child and then drive home again (two more car trips). This totals four trips per day.
However, not all families who drive will make 4 trips per day. Some may make a trip onwards for a different purpose, e.g. work. Some may park their car & make an onward trip via public transport.
To account for these factors, we use the car driver escort trips per child that was used in the 'Propensity To Cycle Tool' schools layer: "The average number of car driver escort trips per child car trip to school was estimated from the English National Travel Survey as 1.2. Note that this value is greater than 1 because many parents drive their child to school and then make the return trip home, but is less than 2 because some parents drive two or more children to school in the same trip and/or drive to the school and then make a trip for a different purpose." Source Propensity to Cycle Tool schools’ layer
In practical terms this means that we can assume a rate of 1.2 car trips per pupil. So you take the number of pupils modelled as driven to school, and multiply it by 1.2 You repeat the same exercise in the afternoon.
For our London example the calculation looks like this:
200,000 pupils x 1.2 car trips/pupil = 240,000 drop off car trips
200,000 pupils x 1.2 car trips/pupil = 240,000 pick up car trips
Total = 480,000 car trips per day
Estimating numbers of cars
There are often times, for example when implementing school streets when it can be helpful to use our data to estimate how many cars (as opposed to total car trips above) can be attributed to the school run. In this example we look at how many cars there might be around a school in the context of implementing a school street.
STEP 1 - Find out how many pupils are driven to school.
Use our primary school travel dashboard to estimate how many pupils are driven to school.
Go to the OVERVIEW section of our London primary school dashboard.
Use the filters to select the borough, ward, school type or school that you want to focus on.
The modelled numbers of pupils driven to school for that selection will display. These numbers were modelled using the actual distances that pupils are travelling to school and combining them with the London average driving rates for those distances. You can find out more about our methodology here.
In the example below, we have selected a school in Lambeth
We can see that the numbers of pupils driven to the school is 84 and the school has a modelled driving rate of 29%.
STEP 2 - convert the number of pupils driven to school into numbers of cars
The main consideration here is that there will be more than 1 pupil in some cars where siblings attend the same school.
The average number of children per family is 1.7, However, not all siblings will attend the same school, some will be younger pupils at nursery, some will be older siblings at secondary school, some independent primary schools are single sex.
We therefore need to reduce this number to reflect how many siblings would be attending the same school, this is not an exact science but we think reducing it to around 1.4 is a reasonable estimate.
Therefore in this example:
85 pupils / 1.4 pupils per car = 65 cars can be attributed to the school run in the morning & similar in the afternoon for this school.
This can be a helpful number to have when comparing against known traffic flows in the area or planning a school street etc.
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