Arrival Window and Buffer: How Early Should You Get There?

If you are heading to an airport at a busy time, the honest answer to "how early should I arrive" is that it depends on two things: how often the transfer runs, and what happens if you miss it. This article sets out a buffer method using those two variables, drawing only on the transfer information published on the official Gatwick and Heathrow parking pages. Where the evidence does not cover a point, this article says so and names the page you need to check yourself.

The two variables that set your buffer

Most arrival-buffer advice collapses into a single number, which is why it so often fails at peak times. A more reliable method treats your buffer as the product of two separate questions:

1. Transfer frequency. How long is the gap between one shuttle and the next? A frequent service absorbs a missed bus with a short wait; an infrequent one turns a small delay into a long one.
2. Consequence of a missed slot. If missing one transfer only costs you a few minutes, you need less slack. If it costs you an hour, you need more.

Both variables are visible in the published timings for the two London airports covered here, and they point in opposite directions. That is why copying a single "arrive X hours early" rule from one airport to another is unreliable.

Gatwick: long-stay shuttle frequency and journey time

At Gatwick, the free shuttle buses between the Long Stay car parks and the terminals run 24 hours a day, 365 days a year. The published journey time to the South Terminal is around 5 to 10 minutes, and about 10 to 12 minutes to the North Terminal. Buses typically run every 10-12 minutes.

Crucially for buffer planning, the same source adds a peak-time caveat: during peak times the buses may be busy, so you might need to wait for the next one. That single sentence is the whole reason a peak-time buffer differs from an off-peak one. If the service is nominally every 10-12 minutes but you may be left behind at peak, your realistic worst-case wait becomes two intervals rather than one, plus the journey itself.

You can read the full wording on the Gatwick parking FAQs page.

Working out a Gatwick long-stay buffer

Using only the published figures, a conservative planning assumption is:

• Wait for the first bus: up to 10-12 minutes in normal conditions.
• If the bus is full at peak: potentially a second interval, so up to roughly two intervals.
• Journey to the terminal: 5-10 minutes (South) or 10-12 minutes (North).

Add those together and you get a transfer-side buffer of roughly 15-24 minutes off-peak, stretching to around 25-36 minutes if you assume you are left behind once at peak. That is the transfer component only. It does not include check-in, security or bag drop, because the evidence bundle does not state those times. For those, check the official airport guidance for your terminal.

Heathrow Park & Ride: a fixed 15-minute interval

Heathrow's Park & Ride page publishes a cleaner, more fixed pattern. Shuttles run between the car park and the terminals every 15 minutes. Transfer times to the terminal doors vary by terminal:

The page also states that transfers run daily between 04:00 and 23:30, and that outside standard transfer bus hours (23:30-04:00) you can request a transfer by calling 020 8745 6261.

That overnight detail is the most important part of the Heathrow buffer calculation, and it is easy to miss. If your arrival falls inside the standard hours, your buffer is built around a 15-minute interval plus the terminal transfer time. If it falls outside those hours, the service is not a scheduled shuttle at all, it is a requested transfer, so the interval logic no longer applies and you should treat the published phone number as the source of truth.

Full details are on the Heathrow Park & Ride page.

Working out a Heathrow Park & Ride buffer

• Wait for the shuttle: up to 15 minutes if you have just missed one.
• Transfer to the terminal: 7-20 minutes depending on terminal.

That gives a transfer-side buffer of roughly 22-35 minutes for Terminals 2 and 3, 22-30 minutes for Terminal 4, and 22-25 minutes for Terminal 5, assuming you arrive at the stop just after a shuttle has left. Again, this excludes check-in, security and bag drop, which are not stated in the evidence bundle.

How early should I arrive?

Neither source page states a recommended arrival time before a flight. The evidence bundle gives transfer timings, not check-in deadlines, so any total "arrive X hours early" figure would be invented. What the bundle does support is a transfer buffer, and that is the part this method can properly answer.

Build your arrival time in three layers:

1. Transfer buffer from the tables above, based on the published interval and journey time at your airport and terminal.
2. Peak uplift if you are travelling at a busy time, because Gatwick explicitly warns that buses may be busy and you might need to wait for the next one.
3. Everything else — check-in, bag drop and security — which you must take from your airline or the official airport page, because this bundle does not cover it.

If you want to compare parking products before you fix your arrival time, see our comparison section, and for the wider trip-planning sequence see Planning.

What if I am late?

The consequence of being late depends entirely on which of the two transfer patterns you are on.

On a frequent Gatwick service, arriving late usually costs you one interval, or two if the bus is full at peak. The published pattern is every 10-12 minutes, so the cost of a small delay is bounded and small.

On the Heathrow Park & Ride during standard hours, the cost is a fixed 15-minute wait plus the transfer time, because the interval is stated as every 15 minutes.

On the Heathrow Park & Ride outside standard hours, the position changes. The page states that between 23:30 and 04:00 you can request a transfer by calling 020 8745 6261. It does not state how long that requested transfer takes to arrive, so a late arrival in that window is the one case where the bundle cannot give you a reliable wait figure. If your trip falls in that window, call the published number and confirm before you travel.

Peak time effect

Peak time affects the two airports differently, and that difference is the core of this method.

• Gatwick: the interval is not the problem; capacity is. Buses typically run every 10-12 minutes, but during peak times they may be busy, so you might need to wait for the next one. Your buffer must cover a possible extra interval.
• Heathrow: the interval is fixed at every 15 minutes during the stated standard hours. The published peak caveat is not present in the bundle for Heathrow, so this article does not assume one.

In short, at Gatwick the peak effect is a capacity effect on top of a frequent service. At Heathrow the stated pattern is a fixed interval within defined hours. Neither page states how long peak queues at check-in or security might be, so that part of your buffer must come from elsewhere.

What this bundle does not tell you

To keep this method honest, here is what is not stated in the evidence and therefore cannot be answered here:

• Recommended arrival times before a flight.
• Check-in, bag drop or security processing times.
• Any minimum or maximum arrival window, or any rule about being refused entry if you are late.
• How long a requested overnight Heathrow transfer takes to arrive.
• Whether the Gatwick shuttle interval changes at specific peak hours.

For those, check the relevant official airport page directly — the Gatwick parking FAQs and the Heathrow Park & Ride page linked above are the two pages this article is built from.

The method in one line

Set your buffer from the published interval plus the published journey time, add an extra interval if the source warns the service may be full at peak, and treat any out-of-hours requested transfer as a case where you must confirm by phone rather than assume a schedule. Then add the check-in and security time from your airline or airport, which this evidence does not supply.

Checked 2026-10-06. This source check uses Parking FAQs and Heathrow Park & Ride. It is not a live availability check, booking or personal test.