What Is a Bi Folding Gate? How Bifold Speed Gates Work and When to Specify One
- A bi folding gate, or bifold gate, has leaves hinged in pairs, so each side folds in half as it opens instead of swinging out as one long leaf.
- Short leaves travel short arcs, which is why bi folding gates usually open faster than slide or swing gates of the same width and are often called speed gates.
- A bi folding gate needs roughly half the swing space of a swing gate and none of the run back space of a slide gate, which suits tight, busy entrances.
- ASTM F2200 lists horizontal bifold gates among the automated gates it covers and requires a UL 325 operator. A bi folding gate is crash rated only if the complete gate passed an ASTM F2656 crash test.
A bi folding gate is a vehicle gate whose leaves are hinged in pairs, so each side folds in half as it opens. Because the leaves are short, the gate clears the lane quickly and needs little room on either side, which is why bi folding gates are used at busy entrances on tight sites. This guide explains how a bi folding gate works, how it compares with slide and swing gates, which standards apply, whether it can be crash rated and how to specify one.
What Is a Bi Folding Gate?
A bi folding gate is a vehicle gate with each side split into two leaves joined by hinges, so the side folds back on itself as it opens. It is also written bifold gate or bi fold gate, and the fast automated versions are sold as bifold speed gates.
Most commercial bi folding gates are bi parting: two pairs of leaves meet in the middle of the opening and fold back toward the posts on each side. ASTM F2200, the standard specification for automated vehicular gate construction, lists horizontal bifold gates as one of the gate types it covers, alongside slide, swing, vertical lift and pivot gates.
How Does a Bi Folding Gate Work?
A bi folding gate opens much like a bifold closet door. An operator at the hinge post drives the leaves, and a folding arm or linkage makes the outer leaf fold back against the inner leaf as the pair swings open. Closing runs the same motion in reverse.
There are two main designs. A trackless bi folding gate carries the leaves entirely from the hinge posts, so nothing sits on the ground inside the opening. A tracked design runs a wheel or guide in a channel set in the driveway, which supports long leaves but has to be kept clear of debris, snow and ice.
Why Are Bi Folding Gates Called Speed Gates?
Bi folding gates are called speed gates because they usually open and close faster than slide or swing gates of the same width. Each leaf is short, so it travels a short arc, and a bi parting gate splits the opening between two sides, so neither side has far to move.
Speed matters at entrances that carry steady traffic. A gate that clears the lane quickly keeps vehicles from queuing back into the street, and a gate that closes quickly shortens the time the opening stands open behind each authorized vehicle, which helps reduce tailgating.
The term speed gate is also used for pedestrian turnstiles with glass wings. A bi folding speed gate is the vehicle version, used at driveways rather than building lobbies.
What Is the Difference Between a Bi Folding Gate, a Slide Gate and a Swing Gate?
The main differences are how the gate moves and how much space it needs. A bi folding gate folds in half, a slide gate rolls along the fence line and a swing gate pivots as one leaf on each side.
| Bi folding gate | Slide gate | Swing gate | |
|---|---|---|---|
| Movement | Each side folds in half as it swings open | One panel rolls along the fence line | One leaf per side swings through a full arc |
| Space beside the opening | Little; the folded leaves sit at the posts | Run back space along the fence for the gate and its tail | Little at the posts |
| Space in front of or behind the opening | Roughly half the swing arc of a swing gate | None | A full arc as deep as each leaf is wide |
| Ground in the opening | Clear on trackless designs | Clear on cantilever designs, a track on V track designs | Clear |
| Opening speed | Usually the fastest of the three | Slower as the opening gets wider | Slower as the leaves get longer |
| Best suited to | Busy entrances on tight sites | Long fence lines with room to the side | Lower traffic entrances with room for the swing |
For slide gates in detail, see our guide to cantilever gates, and for a side by side on access points, see sliding gates and bi folding gates.
Where Are Bi Folding Gates Used?
Bi folding gates are used where an entrance carries steady traffic and the site has little room for a gate to slide or swing. The fold keeps the gate close to its posts, so the gate fits between a building, a guard booth, landscaping or a public sidewalk.
- Data center and corporate campuses: staff and contractor entrances that cycle all day.
- Logistics yards and distribution centers: truck entrances where a queue would back into the road.
- Utility and industrial sites: entrances where the fence line beside the opening is already taken.
- Parking structures and secure lots: entrances with a short approach and no room for a swing arc.
Our post on why speed gates suit modern access control covers how bi folding gates tie into readers and access control systems.
What Standards Apply to Bi Folding Gates?
Two standards apply to every automated bi folding gate, and a third applies when the gate has to stop a vehicle.
| Standard | What it covers | When it applies |
|---|---|---|
| ASTM F2200 | Construction of automated vehicular gates, including horizontal bifold gates | Every automated bi folding gate |
| UL 325 | Safety of gate operators, including entrapment protection, by usage class | With ASTM F2200 on every automated gate |
| ASTM F2656/F2656M | Full scale crash testing of vehicle security barriers | Only when the gate must stop a vehicle |
ASTM F2200 requires automated vehicular gates to comply with UL 325 as well. UL 325 sorts vehicular gate operators into four usage classes, from Class I for residential gates to Class IV for restricted access sites, so name the class that fits the site in the specification.
Can a Bi Folding Gate Be Crash Rated?
A bi folding gate can be crash rated only if the complete gate, with its operator, posts and foundations, has passed a full scale crash test under ASTM F2656. Most bi folding gates are access control gates, built to open and close fast, not to stop a vehicle.
Where an entrance has to stop a vehicle, pair an access control bi folding gate, such as BSP’s bi folding speed gate, with a crash rated active barrier such as wedge barriers or drop arm barriers, and ask for the crash test certification for the configuration being supplied. For how ratings work, see ASTM F2656 crash ratings explained.
How Do You Specify a Bi Folding Gate?
Specify a bi folding gate by its opening, the space around it, how it is automated and whether it must stop a vehicle. Six points cover most specifications:
- Opening and leaf layout: state the clear width and height and whether the gate is bi parting or folds to one side.
- Fold space: confirm which side the leaves fold toward and that the folded leaves and their swing path are clear of curbs, booths and pedestrians.
- Track or trackless: choose trackless where the driveway must stay clear, or a tracked design where the leaves need ground support.
- Automation and safety: require ASTM F2200 construction and a UL 325 listed operator in the right usage class, with the entrapment protection UL 325 calls for.
- Vehicle threat: if the entrance must stop a vehicle, name the ASTM F2656 rating and require the crash test certification, or pair the gate with a rated barrier.
- Fence line tie in: match the gate to the fence system, such as SecureMesh welded mesh or SecurePale palisade, so the opening is not the weak point.
See BSP’s active vehicle barriers and security fencing for the systems a gate ties into.
Bi Folding Gate FAQs
What is a bifold gate?
A bifold gate is a vehicle gate with each side split into two hinged leaves, so the side folds in half as it opens. Most commercial bifold gates are bi parting, with two pairs of leaves meeting in the middle.
How does a bi folding gate work?
An operator at the hinge post drives the leaves, and a folding arm or linkage folds the outer leaf back against the inner leaf as the pair swings open. Closing reverses the motion.
Are bi folding gates faster than sliding gates?
Usually. Short leaves travel short arcs, so a bi folding gate clears the lane faster than a slide gate of the same width, which has to roll its full length along the fence.
How much space does a bi folding gate need?
Very little to the side, because the folded leaves sit at the posts. In front of or behind the opening it needs roughly half the swing arc of a swing gate of the same width.
Do bi folding gates need a track?
Not always. Trackless bi folding gates carry the leaves from the hinge posts, so nothing sits on the ground in the opening. Some designs use a floor track to support long leaves.
Are bi folding gates crash rated?
Only if the complete gate has passed a full scale crash test under ASTM F2656. Most bi folding gates are access control gates; where a vehicle must be stopped, pair the gate with a crash rated barrier.
Need a Gate for a Tight, Busy Entrance?
Send us the opening width, the space on each side, the traffic the entrance carries and whether it must stop a vehicle, and we will recommend a gate and barrier configuration and supply the submittal package.
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