London Marathon Start Zones: Colours, Waves and Timing

A runner's race number for London carries two pieces of information that matter more on the morning than the number itself. One is a colour: Red, Blue or Green. The other is a wave. The colour says which of the three start lines on Blackheath and Greenwich Park the runner belongs to, and so which station they should travel to and which assembly area they can enter. The wave says when, within that start, they will be released onto the road. Neither is chosen. Both are allocated by London Marathon Events.

That is the short answer to how the London Marathon start zones work. And the most important point follows from it: the clock that counts is the runner's own. A chip in the bib is read by timing mats on each start line, so a runner in the last wave of the morning, crossing the line long after the gun, is timed from the moment they step over the mat. Starting late costs nothing on the result. Arriving late at the wrong start can cost a great deal more.

What the colour and wave on a London Marathon bib mean

The race has outgrown any single start. Tens of thousands of runners could not be packed behind one line on the roads of south-east London, and the organisers' FAQs describe assembling more than 50,000 participants on the start line as a mammoth task. The solution, in place in some form for decades, is to split the field across three start areas whose routes join in the opening miles, and then to release each start's field in groups.

Each runner is placed in one start and one wave. The assembly area is the fenced space where runners gather, change, drop their bags and use the toilets. The pen is the section of road behind the line where a wave waits to be released. The start line is where the timing mats lie. All three are named on the race number or in the event guide that comes with it.

Why the allocation is not the runner's to choose

The colour and wave are set by the organisers on the basis of the runner's entry route and the finish time they predicted when they applied. The aim is to put people of similar pace together, so that a three-hour runner is not stuck behind a group walking from the first metre, and so that the three starts carry roughly balanced loads onto the merged road. Letting runners pick would undo both aims within a year, because everyone would want the nearest station and the earliest wave.

What is on the bib	What it decides	Can it be changed
Start colour	Which assembly area and start line to use, and so which station to travel to	No
Wave	When the runner is released from the start line	Only to a later wave, never an earlier one
Race number	Identity, results, medical details, the chip	No; entries cannot be transferred
Baggage label	Which lorry carries the kit bag to the finish	Follows the colour and number

The three start lines on Blackheath and Greenwich Park

The three starts sit close together on the high ground south of Greenwich. As laid out in recent editions, the Red start is on Charlton Way, at the southern edge of Greenwich Park. The Blue start is on Blackheath itself, along Shooters Hill Road, the main road crossing the heath. The Green start is close beside it, in St John's Park on the heath's eastern side. Exact positions and the layout of each assembly area are printed in the event guide for each edition, and they have shifted as the field has grown.

The heath is open common land, which is why it suits a marathon start: there is space to put up fencing, toilets and lorries on grass, and wide roads across and around it to take the runners away. The trade-off is exposure. Blackheath is high and unsheltered, and on a cold or wet April morning a long wait there is properly uncomfortable. Experienced London runners bring an old jumper or a bin bag to wear until the last minutes. Clothing discarded at the start is collected and given to charity.

Further assembly areas as the field has grown

The three colours are the start lines. As the field has grown, the organisers have at times split the larger starts into more than one assembly area, or added space for particular groups, without adding a fourth line. A runner should not assume the layout they remember from a previous year still applies. The map in the current event guide is the only reliable one.

Start	Location in recent editions	Joins the main course	Nearest ground
Red	Charlton Way, southern edge of Greenwich Park	In Woolwich, just before mile 3	The Greenwich Park side
Blue	Shooters Hill Road, Blackheath	In Woolwich, just before mile 3	The open heath
Green	St John's Park, Blackheath	In Woolwich, just before mile 3	The eastern side of the heath
All three	One course from Woolwich	The whole field on one road	Through to The Mall

Who is sent to which London Marathon start zone

The broad pattern has held for years even as the detail has moved. The elite fields, and the championship runners immediately behind them, assemble at the front of one start with an enclosure of their own. How the championship field is treated there is set out in our guide to championship entry and the club rules that go with it.

Good For Age runners have generally been placed together near the front of their start, ahead of most of the mass field, because their entry rests on a proven time. The smaller Green start has historically taken particular groups the organisers want to keep together, and much of the ballot and charity field has historically gone to Red. The organisers have changed the allocation of groups between colours from one edition to the next, and in the 2027 two-day edition the qualifying fields are split by sex across the two days, so no past pattern is a guarantee. The bib is the authority.

Why the colour is allocated and never chosen

There is a capacity question behind it. Each start has a fixed number of runners its pens, toilets and baggage lorries are built for, and the volume leaving each start has to be matched to what the road can take where they merge. If a few thousand runners chose the start nearest their hotel, one colour would be overloaded and another half-empty. The organisers allocate the colours to keep the numbers in balance and do not take requests.

There is also a pace question. Each start runs on its own road for nearly three miles before the fields meet in Woolwich, and those separate roads are where each field has room to string out before it joins the rest. The organisers do not publish their reasoning for each allocation, and the numbers sent to each colour have to be matched to the width of the road it leaves on.

How the London Marathon start waves work

From 2021 the mass field has started in waves. Before then, the London Marathon had a single mass start: once the gun went, every runner on each start moved forward together, and those at the back could take a long time to reach the line. The staggered start introduced for the 2021 race, held in October that year, was one of the measures intended to spread runners out. It has stayed since, because it worked better than the old system for reasons that had nothing to do with the pandemic.

Each start's field is divided into waves of a few thousand runners. A wave is released, walks forward to the line and crosses it; the next wave moves up into the pen behind; and after a gap of a few minutes it is released in turn. Across all three starts, the release of the full field stretches over more than an hour.

How the predicted time decides the wave

The finish time entered on the application form is the main input. Faster predicted times go in earlier waves, slower ones in later ones. That is why the time on the entry form is worth thinking about. A wildly optimistic prediction puts a runner in a wave of people who will be running much faster, which is uncomfortable for everyone. A cautious one puts them among slower runners and means passing people for the first several miles. An honest estimate based on recent races serves the runner and those around them.

Qualifiers with a proven time, such as Good For Age entrants with their published standards, are placed on the strength of the time they qualified with.

What the waves changed

Under the single mass start, a runner at the back of the Red start might take many minutes to reach the line and then spend the first miles walking and jogging in a crush. The waves do not make the start uncrowded, but they mean every runner reaches the line in a group of similar pace and finds some space within a mile or two. They also spread the load on toilets and baggage and reduce the crowding where the starts merge in Woolwich.

The cost is time on the heath. A runner in a late wave may wait a long while after the gun before reaching the line. The organisers time the release so that everybody is on the road within a reasonable window, but the later waves inevitably finish later in the day.

1. 1TravelThe runner takes the train to the station given for their start colour, showing their race number where free travel applies
2. 2Walk to the startSigns and marshals direct runners across the heath or through the park to the right assembly area
3. 3Enter the assembly areaRace numbers are checked at the entrance; only runners for that colour are admitted
4. 4BaggageThe kit bag is handed to the lorry carrying the runner's number range, to be collected at the finish
5. 5Final preparationsToilets, water and the last layer of warm clothing, discarded before the pen
6. 6Enter the penThe runner joins their wave's pen before it closes, with bibs checked at the entrance
7. 7ReleaseThe wave walks forward to the line and crosses the timing mats, which start the runner's own time

The general sequence in recent single-day editions; the clock times and the order of entry to each area are published in the event guide each year.

The order of the morning: elites first, then the waves

The elite races do not start at the same moment as the mass field. In single-day editions the elite wheelchair races and the elite women's race have set off ahead of the main event, separately, so that they have a clear road. The elite men have then started at or just before the first mass wave, with the championship field directly behind them. The order and the gaps between them have varied by edition, so this page does not give clock times for a past race as though they were fixed.

For the 2027 two-day edition the organisers have said that the Saturday race is likely to start at 09:00 and the Sunday race at 09:30, and that the male and female Elite, Championship and Good For Age races will take place on separate days. The broader arrangements, with the men's qualifying fields on one day and the women's on the other, are set out in our guide to the London Marathon ballot and its two-day draw.

The wheelchair races

The elite wheelchair athletes start ahead of the runners and race on the same course. They are among the fastest athletes on the road, and their start is timed so that they are well clear of the elite runners and the mass field. How their race is organised, and how the chairs themselves are regulated, is covered in our guide to the London Marathon wheelchair race.

Why the elite start times matter to the mass field

For most runners the elite start is a moment to watch on the screens in the assembly area. It also sets the morning's clock. The pens for the earliest waves close a set time before the elite men and the first mass wave are released, and every later wave's timing follows from it. A delay to an elite start, for weather or security, moves every wave behind it.

Moving between waves: back yes, forward never

This is the rule runners most often ask about, and the organisers' FAQs state it plainly: participants cannot move forward within their start area, but may move backwards.

The logic is straightforward. A runner who drops back to a later wave will be among slower runners, which causes nobody trouble. A runner who moves forward into an earlier wave will be among faster runners, blocking the road and undoing the purpose of the system. So the rule permits one direction and forbids the other.

Running with a friend

The common case is two friends in different waves of the same colour who want to run together. The faster one may drop back to the slower one's wave. The slower one may not move up. If both are prepared to start later, both can drop back to the same wave and cross the line together.

Changing colour

Not possible. The colour is a start line, an assembly area, a baggage system and a station. A runner cannot enter an assembly area other than the one printed on the bib. Two friends allocated different colours will start separately, and the earliest they can meet on the road is at the merge point, which is not until Woolwich. Many such pairs arrange a meeting point just after the merge.

How the pens are policed

Marshals check race numbers at the entrance to each pen. Runners for the wrong pen are turned away. Volunteers stand at the front of each pen and hold the wave back until it is released. With so many runners passing in a short time the checking is fast rather than exhaustive, but the colour and wave are printed large on the bib so that a glance is enough.

Which station for the Red, Blue and Green starts

The assembly areas are served by the rail stations of south-east London, and the event guide tells each runner which station to use for their colour. The geography explains the advice. The Red start, on the Greenwich Park side, is closest to the stations north of the park and the heath. The Blue and Green starts, on the heath itself, are nearest to the stations on its southern and eastern edges. Blackheath station sits at the foot of the heath on the south-west side, while Greenwich, Maze Hill and Westcombe Park lie on the lines further north towards the river. Which station is recommended for which colour is confirmed in the event guide each year, and runners should use the one they are given rather than the one that looks nearest on a map.

Travel on the morning

In recent editions runners have been able to travel free on race morning on Transport for London services and the main rail operators into south-east London by showing their race number. The arrangement and the operators covered are confirmed each year in the event guide. Trains are busy, and the operators run extra services. A runner staying in central London should allow far longer than the journey normally takes.

The walk from the platform

The stations are not at the start lines. From Blackheath or the stations near Greenwich Park, the walk to an assembly area can take a quarter of an hour or more, uphill in places, in a crowd. Runners should add that to their journey time and to their plan for the morning.

Why driving is not an option

The roads around the starts are closed, and there is no parking for runners near the assembly areas. Some runners are dropped off nearby by family, but that requires knowing which roads are open and arriving very early. For almost everyone, the train is the only practical way to reach the start.

Inside the assembly area: baggage, toilets and the pens closing

The assembly areas open early on race morning. Inside each one, runners find the same set of facilities: baggage lorries, toilets, water, changing space on the grass and screens showing the elite races.

Baggage

Each runner receives an official kit bag with their race number on it. The bag is handed to the baggage lorry for the runner's number range, and the lorries are driven to the finish area, where the runner collects it after the race. Only the official bag is accepted, and the organisers limit what may go in it. The lorries leave the start at a set time, so a bag handed in too late will not be taken.

Toilets

There are a great many toilets at each start, and there are still queues. Experienced runners join a queue soon after arriving rather than waiting until the pens open, because the queues lengthen as the start approaches. The organisers' course information also lists toilets at every mile from mile one to mile twenty-four, which takes some of the pressure off the start.

Water and warmth

Water is available in the assembly areas. On a cold morning, the most useful thing to carry is an old layer that can be discarded at the pen. On a warm one, shade and a seat on the grass matter more than anything.

The time the pens close

Each wave's pen closes a fixed time before that wave is released, and the times are printed in the event guide. A runner who arrives at the assembly area after their pen has closed is not turned away from the race. In practice they are directed to join a later wave, and their chip time still starts from the moment they cross the line. The real risks of a late arrival are a missed bag drop and a rushed, stressed start, not exclusion.

Planning the morning backwards from the wave

The useful way to plan race morning is from the wave time backwards, not from the alarm forwards. Take a runner whose wave is due to be released roughly an hour after the first mass wave. Their pen will close a set time before that, as printed in the event guide. Before the pen they need time for the toilet queue, which on a busy start can be long, and before that the baggage lorries, which leave at a fixed time regardless of the runner's wave. Before the assembly area comes the walk from the station, and before that a train that will be fuller than any commuter service.

Added up, most runners find they need to leave central London far earlier than their wave time suggests, and a runner in a late wave can still be caught out by a baggage deadline that applies to everyone on the start. The commonest mistake on the heath is not arriving late for the pen. It is arriving in good time for the pen and too late for the bag drop.

Late-wave runners have a further thing to plan for: food. Someone released well after the first wave may be crossing the start line three or four hours after breakfast, and a small snack carried to the assembly area is worth more than any gel on the course.

1. 1Pen closedThe runner reaches the assembly area after their own wave's pen has closed
2. 2Directed backMarshals send them to a later wave in the same start colour
3. 3Baggage checkedIf the baggage lorries have left, the runner must keep their bag or leave it behind
4. 4ReleaseThe runner starts with the later wave, crossing the same timing mats
5. 5Result unaffectedChip time runs from the moment they cross the line, so the late start costs no time on the result

The general approach in recent editions; the cut-off times for pens and baggage are set in each year's event guide.

Chip time and gun time at the London Marathon

Every runner has two times. The gun time runs from the official start signal to the moment they cross the finish line. The chip time runs from the moment they cross the start line, as read by the timing mats, to the moment they cross the finish. For an elite runner on the front row the two are almost identical. For someone in a late wave they can differ by a great deal.

World Athletics rules make the gun time the official time. The time from crossing the start line to crossing the finish can be made known to the athlete, but its rules say it is not an official time. That is why championship positions and records rest on gun time and the order of crossing the line. For the mass field, the organisers publish the chip time as the runner's own result, and it is the figure most runners quote.

Which time counts for what

Purpose	Time used	Why
Elite and championship positions	Gun time and finishing order	Competitors are racing each other from the same signal
Records	Gun time	World Athletics rules make it the official time
A runner's own result	Chip time	It measures the runner's own run from line to line
Qualifying for later races	Depends on that race's rules	Each race states which time it accepts, so check its criteria
Tracking on the day	Chip splits at each timing mat	The mats read the chip at regular intervals

Why a late wave costs nothing

Because the runner's own result is chip time, starting in the last wave rather than the first does not change it. The clock above the finish shows the gun time, which can alarm a runner who forgets they started late. The time recorded against their name is their own.

Where the start routes merge and why it matters

Three starts become one course in the first three miles. The organisers' course description says runners from the three start lines meet for the first time just before the third mile marker, in Woolwich, near the Royal Artillery Barracks. From there the whole field runs as one. How the course continues from Woolwich to The Mall is the subject of our mile-by-mile guide to the course.

Balancing the load

The organisers time the release of the waves on each start so that the road beyond each merge point is not overloaded. If all three starts released large waves of the same pace at the same moment, the runners from each would converge in Woolwich in a crush. Staggering the waves and balancing the numbers on each start keeps the merged road moving.

For runners, the merge is often noticeable as a sudden thickening of the field. A Red runner reaching Woolwich finds themselves among Blue and Green runners of similar pace who started on different roads.

Pacers across the three starts

London has official pacers, runners who aim to finish in a given time and whom others can follow. For 2027, the organisers' FAQs say the pacers cover target finish times from 2 hours 45 minutes to 7 hours 30 minutes, and times in between. Each pacer carries a flag or marker showing the target time.

• 2.75Fastest official pace group, hours
• 7.5Slowest official pace group, hours
• 7.75Saturday time limit, hours
• 3Start lines

From London Marathon Events' FAQs for the 2027 two-day edition; the Saturday limit was set so that roads could be reopened before the Sunday race.

Why your pacer may not be in your pen

The pacers are distributed across the three starts and the waves, so that every part of the field has some. That does not mean every pen has every target time. A runner whose wave has no pacer at their target may find one on the road after the merge, or may need to run the early miles on their own watch. Pacers usually run even splits, which suits a flat course.

There is a trade-off to running with a pacer. The group around a popular pacer can be large and tightly packed, which makes drinks stations awkward and corners slow. Some runners prefer to run a few metres ahead or behind the group, keeping the flag in sight without being in the crowd.

The back of the field: the last wave and the closing of the course

At the back of the London Marathon is the slowest part of the field: runners, walkers, people in heavy costumes and charity runners who have trained to finish rather than to race. The final wave leaves the start long after the gun, and the back of the field moves at walking pace.

Behind the last runners come the vehicles that close the course. As they pass, roads begin to reopen to traffic. A runner who falls behind them is no longer on a closed course and may be asked to move onto the pavement, to stop, or to continue at their own risk.

The 2027 time limits

The 2027 two-day edition sets different limits for each day. On Saturday 24 April, the finish line on The Mall closes at 17:30, which the organisers put at a maximum of 7 hours and 45 minutes on the course, so that the roads can be reopened before the Sunday race. On Sunday 25 April, the organisers have arranged a secondary finish line in Green Park that closes at 23:59:59. Those falling behind eight-hour pace on the Sunday may have their bibs scanned manually by course staff rather than being timed by the usual mats.

What the organisers say about finishing late

The detail has varied between editions, and this is one area where the organisers' wording for the specific year matters more than anything written here. In general, a runner behind the closing vehicles is no longer on a closed road and must follow marshals' instructions; whether a time is recorded, and where the medal is collected, are set out in that year's event guide. The 2027 Sunday arrangement, with manual bib scans for anyone behind eight-hour pace and a finish open until midnight, shows the organisers planning for a long tail rather than cutting it off. A runner who expects to be near the back should read the current guide closely.

The back of the field is not the least important part of the race. It is where the costumes, the fundraising and the stories are. Every finisher gets the same medal, and the runner who finishes last has covered the same distance. More on the race and on road running across England sits on our athletics coverage, our guide to the biggest half marathons in the UK and across the England hub.