Central Park loop or the Hudson River Greenway

The two routes, measured

Only one of them comes back.

New York has two curated routes. The Central Park Full Loop is 9.89 km, paved, closes on its own start and contains two corners. The Hudson River Greenway is 8.12 km, paved, runs point to point and contains six.

Read those numbers narrowly. Each distance is the length of one specific recorded shape, not of the park or the path in general. The Central Park Conservancy's running guide, checked on 2 August 2026, states that the longest loop in the park totals 6.1 miles, about 9.8 km, which lands within roughly a hundred metres of the measured route. The estimated times are calculated from the route data, not taken from anybody's recorded run.

The Central Park full loop

One lap is 9.89 km.

That is a 10 km session with a hundred and ten metres missing, which you close by running past your start line and stopping at the next lamp post. Two laps are 19.78 km, which most plans would call a long run.

A closed loop caps how far from the start you can get. At the furthest point on the lap you are about 4.9 km of running from your start whichever way you continue, and you pass the start once per lap, so a bag or a second bottle left at one fixed point is reachable on a schedule and not by luck. Splits are comparable too, because each lap crosses the same ground in the same order.

Shorter circuits exist, and they are not part of the curated route. The same Conservancy guide lists the Reservoir running track as a 1.58 mile loop and the bridle path around it as a 1.66 mile loop, roughly 2.54 km and 2.67 km. Treat those as a plan B you navigate yourself.

The Hudson River Greenway

It is a line, not a loop. The route is 8.12 km through Hudson River Park, so run it end to end and you finish about eight kilometres of path away from where you started. That is the whole planning problem in one sentence. Out and back gives you 16.24 km, and that is a genuine long run, not an easy hour.

A line is more flexible than a loop for setting distance, because the turnaround is yours. Turn at 4 km for an 8 km run, at 5 km for 10 km, at 8 km for 16 km, which is very nearly the whole route out and back.

You do not need to reach the far end for the run to have worked.

Six corners over 8.12 km averages one every 1.35 km. That is still a low count, but it is three times as many corners as the park loop. The published data carries the number of corners and not where they fall, so read 1.35 km as an average and not as a rhythm you can run to.

A loop you cannot really get lost on

Two corners over 9.89 km averages one corner every 4.9 km.

That is more than three times the spacing on the greenway. In practice the route asks you nothing for kilometres at a stretch, and the amount of navigating it demands is close to zero.

You commit at the start and the route does the rest.

That matters if you run alone in an unfamiliar city. Every corner is a decision, and a decision made at pace while hunting for a street sign is where a route run turns into a wander. A loop with two corners removes almost all of them, including the largest one: when to turn back. The distance is fixed the moment you set off.

• Loop, for a known distance
• Loop, for repeated laps, because the splits line up
• Loop, when you are out early or late and want to stay within 5 km of one point, with nothing to arrange at the end
• Line, when you want to pick the distance while you are running it

A line, and what to do at the end of it

Decide how the run ends. Do that before you start it, because the alternative is the single mistake that turns a good riverside session into a long cold walk, and it is entirely avoidable.

1. Choose the shape firstOut and back, point to point with transport home, or a fixed turnaround at half your target. All three are fine. Choosing none of them in advance is not.
2. Set the turnaround, not the totalOn an out and back the turnaround decides everything. Turn at half your target and the total takes care of itself, and you can adjust it while you still feel fresh.
3. Carry what you need at the far endOn a loop you pass your start every lap. On a line you pass it once. Water, a card, a phone that will still have battery in an hour, and enough clothing to stand still at the finish.
4. Check the return before the last kilometreIf the plan is a train or a bus home, confirm the stop and the frequency while you are still running, not while you are cooling down by the water.

One caveat about running a published route out and back. The second half is that same route in reverse, which is not the same thing to an app that is following the route with you.

Corners, and what is announced

Very little. Two corners in Central Park and six along the greenway. Following a curated route means each corner is called out in advance and again at the corner. It is not navigation in the sense a maps app means it, because the app does not reroute and it does not point you back to the route if you leave it.

The counts in the table come from a geometry rule. Runflake computes turn instructions from each route's own shape with its own turn detector before the route is published, and they are not written by hand and not taken from a navigation provider. A bend only becomes a turn if the direction of travel changes by at least 55 degrees measured 35 m before and after the point, and the same 55 degrees must still hold when the bend is re-measured over a wider 56 m window. A long sweeping curve never crosses that threshold inside those windows, which is why a route that bends continuously for kilometres produces almost no turns.

Turns that survive the test are classified into six kinds. Between 55 and 75 degrees is bear left or bear right. Between 75 and 160 degrees is turn left or turn right. Anything above 160 degrees is a U-turn.

Each turn is announced at most twice: once at the route's pre-announce distance, which is 120 m on every curated route and is clamped between 40 m and 300 m, and once again 25 m before the corner. The second call is skipped if the first one already landed closer than 50 m. The next turn appears on screen from 400 m out, earlier than the voice, on the reasoning that a screen you choose to look at cannot interrupt you.

Spoken distances are rounded down before they are read: to the nearest 50 m in metric, to the nearest 10 m below 100 m, and to the nearest 50 ft in imperial. You never hear an odd number like "In 117 meters". The rest of the cues are in what running apps say out loud.

Two behaviours are worth knowing before an out and back. Running a curated route in reverse switches turn cues off entirely rather than mirroring them, and the app tells you why: "You are running this course in reverse, so turn cues are off." A bear left read backwards is not a bear right, and a wrong instruction at a junction is worse than silence. Separately, a gap of up to 5 seconds between usable position fixes does not reset the off route evidence, and turn cues are not pushed forward while course judging is suspended, so a signal gap cannot make the app skip past a corner.

Where the route data comes from

OpenStreetMap, under the ODbL licence. The route shapes in Runflake's curated set come from there and are credited to OpenStreetMap contributors. OpenStreetMap's copyright page, checked on 2 August 2026, sets out the terms: the data is licensed under the Open Data Commons Open Database License, and anyone using it must credit OpenStreetMap and make clear that the data is available under that licence.

Three consequences follow. Distance is the length of a recorded shape, whichever app you use, so your watch will disagree by a little and neither number is wrong.

The corner count comes from a geometry rule applied to that shape, not from a judgement about how the route feels underfoot. The surface field has two values, so it is a shoe decision and nothing more.

A published distance is worth what you can check it against. For Central Park that comparison holds: 6.1 miles from the Conservancy against 9.89 km measured, a gap small enough to be the line you take through the bends.

Where no official length exists you have a measurement and nothing to check it against. The same reasoning applied to corner counts is in city routes with turn cues. Treat the first run of a new route as reconnaissance.