BRIO Track Guide

Genuine BRIO track is constructed from beech wood, a high-quality hardwood with a light color and a fine grain. The use of hardwood provides considerable durability, specifically resisting denting, bruising, and chipping. BRIO track is expensive because it is machined to a very smooth finish with no rough edges, and beveled along the grooves to improve car guidance.

There are several fundamentals to the BRIO wooden railway track that can help you plan your railway system and drive purchasing decisions:

  1. BRIO uses the metric system and is measured in millimeters, not inches. Though BRIO does publish English measurements with its track, these values are rounded to the nearest quarter inch. Always use millimeters when doing measurements.
  2. Curved track divides the circle into eight, 45-degree arcs. The large curve diameter listed in catalogs and track guides does not appear to correspond to any actual measurements on the track. The small curve diameter corresponds to the inside curve diameter, not the centerline diameter.
  3. The fundamental straight track sizes are the A and D track. All other track are divisions of these two sizes.
  4. The fundamental curves are the E and E1 track. All curved switches, curved crosses, and tees are based on their radii.
  5. The male connector (pegs) are smaller than the female connectors (holes). This provides a very loose connection with considerable play in the joint, and allows the joint to be stretched by two or three millimeters and bent by a few degrees without derailing the train cars. Without this flexibility, it would be impossible to create complex layouts as the mathematics of 45 degre angles produce fractional lengths based on the square root of two.

A typical piece of BRIO track is 40mm wide and 12mm high, with two 6mm wide grooves that are 3mm deep, spaced 20mm apart, measuring 26mm from center to center. The male connector is an 11.5mm peg on a 7mm long neck, and the female connector ranges from 15 to 17mm in diameter with a 5mm long throat.

Double track is spaced 46mm from center to center, making it 6mm wider than two track pieces placed side-by-side.

Track Identification

In the sidebar to the right are links to official BRIO Track ID guides. Until the mid 2000’s, BRIO used letter names to refer to the various track pieces. While BRIO seems to have deprecated it, the track guide is quite handy and I enthusiastically embrace its use. You will frequently see references to track by their letter names on this site.

The modern BRIO track ID chart, taken from the 2002 product catalog.

While the track guide is an excellent resource, there are some caveats:

This chart from 2000 shows the double track, as well as the five-point switch as track Q.
  1. BRIO has reused at least two track letter IDs: the T track type used to refer to Classic Supports, product #33355, but now refers to the T-Switch. Track type N1 showed as a double ascending track in 1997 (and may not have been produced), and it was later reassigned to refer to the ascending track with two male connectors. This web site uses the later designations for each.
  2. Not all track types are available for individual purchase. Some have been retired, some are only bundled with track sets or certain accessories, and some was only produced in certain markets. The A3 track, for example, may not have been available in the U.S. and I have only seen it sold in Germany.
  3. A track ID has changed on at least one occasion: the Triple Parallel Switch, also called the 3-Way Parallel Switch, was referred to as track Y and Z in sample layouts published on BRIO’s web site in 1999, but the official track ID guides in the 1998 and 2000 wish books list them as F2 and G2.
  4. Track ID Y was briefly assigned to the autostart/stop track segment in the year 2000 in a UK range guide (that’s Brit-speak for catalog).

The following table describes the individual track pieces listed in track guides.

Track IDNameBase TrackLength (mm)Radius (mm)Comments
A, B, CMedium StraightA144n/a

The A track is one of the core track lengths in the BRIO system. Most switch track has a linear length that matches the A track, which means that a switch can generally be laid in its place, and visa-versa. The exceptions to this are the short curved switch track, O1 and P1. The A track is sold in 4-packs as #33335, the Medium Straight pack.


This is one of the most useful straight track pieces because it serves as the base length for most switching track. If you place a swtich track in a loop, you can drop an A track opposite it to keep your lengths aligned. A track is 2/3 the length of D track.


The B and C track are the same as an A track but with two male and two female connectors, respectively. They were bundled with track sets produced in the 1980's as well as sold in the 80's version of the Medium Straight pack, #33339, which shipped with two A, one B, and one C. They have since been retired. You might come across them when purchasing so-called "vintage" sets (off of eBay, craigslist, garage sales, etc.), or when purchasing large lots that have pieces dating back to the 80's.

A1,B1, C1Short StraightD108n/a

The A1 track is one half of the length of the D track. It also is the base linear track for the short curved switches, O1 and P1. A1 track is sold in 4-packs as #33334, the Short Straight pack.


As with B and C, the B1 and C1 track are an A1 length with two male and two female connectors, respectively, and were bundled with some sets in the 1980's as well sold in the 80's version of the Short Straight pack, #33338, which contained two A1, one B1, and one C1. They have also been retired.

A2, B2, C2Mini StraightD54n/a

The A2 track is one quarter the length of the D track. B2 and C2 are the same as A2 only with two male and two female connectors, respectively.


These three pieces are sold as #33333, the Mini Straight pack, which contains two A2, and one each of B2 and C2. They are also bundled in various expansion packs.


These are arguably the single most useful track pieces because they can solve both gender alignment and track gap issues.

A3Middle StraightA72n/a

A straight track that appeared in 2000 and appears to only have had limited distribution and a short life before being retired. It measures 72mm, or one-half the length of an A track.


It is a shame that the A3 track is not widely available, as this is an extremely useful length. There are no other track pieces that are divisions of A, making it very difficult to resolve track gap issues that fall between A1 and A2.


The BRIO track system is in desperate need of a piece of this length, and this is one of the few cases where I recommend using 3rd party track.

DLong StraightD216n/a

The longest straight track produced by BRIO, this track serves as the basis for large track such as K, K1, N, T, and X, and the Grand Turntable. Sold in 4-packs as #33341, the Long Straight pack.

ELarge CurveEn/a182

This curve serves as the base for large curved switch and curved crossing track. Sold in 4-packs as #33342, but it's almost never necessary to purchase separately because it is the single most common piece of track.


The inner radius of E track is just over 182mm, and the outer radius just over 222mm.


Every BRIO starter set and most expansion packs come with E track, and virtually every BRIO collection accumulates more of these than are able to be used. E track is so abundant that you can't even give it away, much less sell it on the used market.

EELarge Double CurveEn/a182

Two parallel curves in one track. The inner track radius is 182mm, matching the E track.


This track is essential for curving two parallel tracks in tandem, as there is no BRIO piece that matches the radius of the "outer" track.


Large double curved track used to be sold in pairs as #33398 and it has since been retired.

E1Short CurveE1n/a90This curve serves as the base for short curved switch, tee, and star cross track. This is a very useful track piece because it provides a tight curve, allowing for complex layouts in confined spaces. Sold in 4-packs as #33337.
EE1Short Double CurveE1n/a90

Similar to EE, but for the E1 track radius.


This used to be sold in pairs as #33399 and has since been retired.

F, GSwitchA150n/a

A straight switch that turns one track into two parallel tracks, and visa versa. Using this switch will shift the center line of your track by creating two tracks that are both offset from the single end. They are also slightly longer than "A" track, measuring 150mm in width.


These tracks are no longer sold separately, and are only seen in accessory bundles. They were formerly sold together as #33348.

F1, G1Parallel SwitchA144n/a

Creates parallel track from a single track without shifting the centerline of the "main" branch, which makes it extremely useful for creating spurs, switch yards, and tight bundles of parallel track. Unfortunately, it is also very hard to find.


These tracks are no longer sold separately, and are only seen in accessory bundles. They were formerly sold together as #33466.

F2, G2Triple Parallel SwitchA144n/a

Turns a single track into three parallel tracks. They were sold together as #33338, and the F2 track was bundled with #33328, the Fix-It Shed. They've both been retired.


When these track first debuted in 1998 they were given the track ID's of Y and Z, but they were later renamed.

HCrossA1108n/a

This is a cross track that comes in two pieces so that the orientation of the male/female ends can be reversed. Each part is an A1 length.


H was formerly bundled with R and S as #33387 for no good reason, and has since been retired.


The original design for H was an A1 length in one direction, and an A length in the other. It was sold in a bundle with F and G as 3342/31405-2, Switching Tracks and Crossing Tracks, in the 70's and early 80's.

H1Crossn/a116n/a

H1 is a strange piece with a very specific use. It is a cross track but the opposite ends have the same connector (male-to-male, and female-to-female). It's straights are 116mm long, which does not match any BRIO standard pieces.


It's designed to form a cross from two or more curved switch tracks. You can fit H1 inside the space of an L and M joined at the curved end, so that the straight tracks cross while the curved tracks form a quarter circle. It can also fit inside the gap formed by joining two I and two J switches together at their curved ends, to make a very large "star" switch.


H1 was sold as #33464 and is no longer available individually. It is now only found in the #33307 Advanced Expansion Pack.

H2 Criss CrossA144n/a

This is two A track crossing at a 45 degree angle.
When it debuted in 1998 it was given a track ID of W.


This piece is almost entirely dependent on the vario system. The geometry of BRIO track is such that two parallel runs of track that are joined together using a switch, either long or short, cannot have a 45-degree crossing that results in a perfect fit using this piece.


Without the vario system, this track would be impossible to use. That does not make it useless, it just means that it is only usable in track arrangements that have considerable play in their joints.


Criss Cross track was sold as #33384 and has been retired.

H3Curved CrossingEn/a182A relatively new track piece, this is a switch that is comprised of two curves that meet in the middle. Basically, two E tracks that are joined together. It can be found in BRIO starter sets that joined two circles together, and in the #33307 Advanced Expansion Pack.
I,JCurved SwitchA, E144182

Sometimes called the Double Curved Switch or the Triple Curved Switch.


This is a three direction switch: straight, left, or right. The curves are based on the E track. This is basically an A track with two E curves joined at one end.


These were sold together as #33347 and they appear to have been retired.

KSwitching and CrossingD216n/a

A long double straight track (K1) with a criss-cross to allow a train to change from one side to the other. This is an extremely useful track piece and it is hard to find.


This has been sold separately as #33345, and as part of #33303, the Shunting Yard Expansion Set, both of which have been retired.

K1Double StraightD216n/a

This is the equivalent of two, parallel D tracks.


Double striaght track used to be sold as #33467 and has since been retired.

L, L1, M, M1Curved SwitchA, E144182

A two direction switch: straight and curved. This is basically an A track and an E track joined at one end. This is the quintessential BRIO switching track, and most BRIO sets cannot get enough of them. Because they are based on A and E, however, they mean more space is required to acommodate complex layouts. O1 and P1 may be more useful in confined spaces.


L1 and M1 are the mechanical switch versions of L and M, primarily for use with battery-operated trains. The mechanical switch ensures that train cars go the intended direction.


L and M are sold together as #33346, and L1 and M1 are sold as #33344.

N, N1AscendingD216n/a

Raises or lowers the track by 64mm. N is sold in pairs as #33332 but it is almost never necessary to purchase it separately as it is bundled with bridges and dual-level accessories. Most BRIO collections accumulate more N track than they need.


The N1 track is an N track with two male connectors. It was bundled with #33397, the Reversible Bridge, a double track bridge with female connectors on both ends..
O, PShort Curved SwitchE1n/a90Confusingly shares a name with O1 and P1. Basically two E1 curves joined at one end, giving you two directions: a curve up and a curve down. Sold as #33350, and now only available in the Advanced Expansion Pack.
O1, P1Short Curved SwitchA1, E110890

Confusingy shares a name with O and P. A two-direction switch: straight and a short curve. This is a straight track, A1, joined with a short curve, E1, at one end.


This first appeared in the early 2000's. Originally sold as #33439, it is now found in #33394 Starter Track Pack and the older #33307 Advanced Expansion Pack.

QFive-Point SwitchA,E144182The five-point switch is bundled with roundhouses, but was also sold separately as #33462. The outer turns are 45 degree angles, and the inner turns are 22.5 degree angles.
R, SBuffer Stopsn/a40n/a

These stops terminate your track with a red-and-white striped vertical barrier. Arguably one of the most useful pieces of BRIO track, and typically in short supply.


Originally these were bundled with H as #33387, the Crossing Track & Buffer Stops, a baffling and almost pointless combination. Currently, it is bundled with U and V as #33385, the Ramp and Stop Track Pack, a far more useful pairing. They are also included in #33307, the Advanced Expansion Pack.

TT-SwitchD, E1†21688

A "tee" track giving three directions at 90 degree angles to one another. Bundled with B2 as #33463, the T-Switch.


The curves in T are very, very close to E1, but because the straight side is a D track they are 2mm tighter.

U, VRamp TracksD54n/aEnd pieces that are ramped to allow cars to enter and exit the track. Very useful for accessories that accept vehicles with removable loads for loading and unloading. Used to be sold as #33331, the Ramp Tracks but now bundled with R and S as #33385, the Ramp and Stop Track Pack.
XStar SwitchD, E1†21688Four track directions at 90 degree angles, and curves to switch between them. X has limited utility because it is a very large piece that requires some planning to use. Originally sold as #33465, the Star Switch, and appears to have been retired.

†Approximate. These radii are within 2mm of E1.