Tern Symbols

Information is needed “to know”. Knowledge is power. Providing information in public space in a way that improves perception of information fosters empowerment of citizens. To this end, Tern Symbols have been introduced to measurably improve visibility of information.

Maximum visibility of information on signs – improving road safety and fostering inclusion

Tern Symbols are crafted to maintain maximum visibility of visual information, despite difficult circumstances, such as movement at high speed, short viewing duration, long viewing distances and bad viewing conditions. This is crucial for adequate information perception in vehicular road traffic, as well as for citizens effected by visual impairments to profit from inclusive information.

Reliable principles and new possibilities

Through the employment of the MOA Design Method’s principles, maximum visibility is established for symbols, which can be precisely followed up through calculation. This also allows to precisely determine viewing distance.

The MOA Design Method represents the result of constant development starting 2005 with EU funded projects SOMS/In Safety, followed by project Safeway2school. Tern Typeface, which adheres to the principles of the MOA Design Method, has become the standard road signage typeface in Slovakia, and is legally binding for use on Austria’s road signs. The Netherlands use Tern VMS Typeface countrywide on Variable Message Signs on roads.

Searching and acquiring Tern Symbols

Tern Symbols System content

The Tern Symbols Set follows the logic of the system of road signs shown in Annex 2 of the UN’s Vienna Convention on Road Signs and Signals, done in Vienna, 1968 (called hereafter “VCRSS”). A country having signed this law of nations is obliged to use its signs on all roads.

Furthermore, additional symbols found necessary by multiple stakeholders, e.g. as established during project SOMS/In-Safety are part of the collection. Both sets are continuously expanded. For updates, check back for a new upload of the TS Search Package found below), or follow @iiidred on Twitter for notification.

Symbol Template content

In a consistent system as the VCRSS, symbols are combined with different basic geometric shapes to communicate different meanings. A bicycle in a triangle is a warning, a bicycle in a circle is either a prohibition, or a bicycle path compulsory to use. Still the symbol “bicycle” remains the same. The Tern Symbols System is based on this principle, to keep the amount of symbols comprehensive. One Tern Symbol Template features the symbol usually in 5 shapes. Due to this, several VCRSS signs may be created using only one Tern Symbol.

File Format

Tern Symbol Template files are vector graphics, provided in PDF format.

Choosing and buying a Tern Symbol

Aside from simply browsing the online shop, you may choose to use a more strategic procedure:

Tern Symbols Search Package

  1. Download:
    TSsearchPackage for easy access to all Tern Symbols currently available. Models of signs shown in VCRSS’ Annex 2 are provided here, alongside corresponding Tern Symbols.
  2. Find:
    Aside from regular excel search funktions,
    TStable2b.xlsx may be sorted by TS code (Tern Symbol number), TS Referent (Tern Symbol name), and by VCRSS code. In addition, depictions of Tern Symbols and VCRSS signs are included for visual identification. Please note that the symbols set includes supplemental symbols exceeding the VCRSS signs set.
    TS1.pdf provides a graphical overview, showing Symbols, TS Code and corresponding VCRSS code.
    VCRSS.pdf, a graphical overview on the UNs’ VSCRSS – signs, complete with codes.
  3. Buy:
    Access iiidre.weebly.com and purchase, you receive a link to directly download the Tern Symbol Template file(s).

For the End-User License Agreement for Tern Symbols, please scroll down to the end of this page.

Working with Tern Symbols, 1:
Maintaining the visibility-maximising properties of Tern Symbols

Proportional use, up- or down- sizing

In order to maintain visibility properties, Tern Symbols, should not be distorted in any way. Instead, they have to be used as provided on the template sheets. Scaling of a symbol to reduce or increase its dimension has to be done strictly proportional.

For correct up- or downsizing, choose one of the five provided shapes (see figure below) from the template that reflects the shape of the background in which you wish to insert the symbol. Group the symbol with the shape and proportionally scale it by fitting it precisely to the target background.

First, group the shape and symbol in the computer application of your choice. Second, scale the group to fit the target background

Figure 1: Scaling – How to up- or downsize Tern Symbols

Every Tern Symbol template provides a symbol enclosed in (up to) five geometric outline shapes reflecting shapes of background used on road signs and other signage systems: Rectangle (rec), square (squ), circle (cir), equilateral triangle (tri), and diamond (dia). The shapes are provided to secure the optimal distance between a symbol and other graphical components, as this is crucial for maintaining Tern Symbols visibility properties.

Tern Symbol shapes and where they occur in VCRSS

Figure 2: Shapes. Tern Symbol shapes and corresponding road sign sections of the Vienna Convention on Road Signs and Signals (VCRSS), in which they occur

Exception: The (rec)tangle. While all other shapes are constant by definition, the rectangle is an exception in three ways.

  1. Its height-to-width ratio varies, according to the form of a symbol.
  2. Because of this inconstancy, the rectangle in some cases matches the (squ)are background shape, to the effect that there is no need for a rec template sheet to be available.
  3. The rectangle shape is supposed to be fitted only to either the horizontal or vertical margins of a targeted background shape, depending on which application makes best use of given space.
Two possibilities to scale rectangular shapes.

Figure 3: Scaling (rec)tangle shape to fit horizontal or vertical margins.

Depending on application, a background may represent either the inner margin of a border, or the outer margin of a (road) sign. If you are working on a road sign, make sure to use borders which are in conformity with national legislation, since quite often, the measurements of the width (or thickness) of borders are precisely defined. If such restrictions do not exist, it is advised to use Tern Symbols Road Sign Borders.

Working with Tern Symbols, 2:
Maintaining properties of a symbol to be understood

Contrast reversion

Generally, all Tern Symbols may be contrast reversed (and sometimes have to, in order create a road sign, see Figure 1), except if it is indicated on the front page of a Symbol Template (“Contrast reversion….NO”). This is due to the fact that some symbols need to closely resemble what it is depicting (see Figure below), as in some cases, it is required that solid forms have solid colour, or have the brightness as in reality in order to be understood as expected.

In some cases it is relevant for understanding of the meaning of a symbol, that solid forms have solid (dark) colour, or that that colours stay unchanged.

Figure 4: Examples of cases where contrast reversion is inappropriate

Symbol reversal

In generally, Tern Symbols may be mirrored to face in the opposite direction, except when it is not recommended in writing on the front page of a Symbol Template Sheet (Symbol reversal). “NO” indicates that a symbol has the properties of indicating a direction, but should not be mirrored. “N/A” implies that this symbol has no properties to allow it to face left or right. In this case, reversal is not recommended, too.

Some symbols have features indicating a direction, some don't.

Figure 5: Symbol features indicating direction

There are three categories for symbol reversal, which apply independent from one another:

  • Countries with left-hand traffic may need this to better fit to drivers needs for understanding.
  • Symbols, typically showing a vehicle, person or animal in side view usually strongly imply direction (in which they face). Therefore, if such symbols are used on direction signs, they should not oppose the bearing of a direction arrow to avoid confusion. If a symbol that implies direction is used for a straight onward heading, it should be used as provided through the Tern Symbol Template Sheet.
If symbol direction opposes arrow direction, confusion of the viewing person

Figure 6: Symbol should not oppose travel direction (examples not exhaustive)

  • Warning signs: To make a warning more evident, symbols may be used to indicate where the source of a danger is located, e.g. wild animals (TS1200) may be presented as to cross the road (when the warning sign is posted on the right side of the road, the symbol should face towards the left and vice versa. If a symbol that implies direction is used for a danger to be expected straight ahead, it should be used as provided through the Tern Symbol Template.
Symbol rotation

Very few symbols have the ability to indicate more directions than left or right- these are the direction arrow TS1620 (Arrow, straight) and TS1510 (Aircraft). They may be rotated (usually in 45° steps). If both are used on the same sign TS1510 should always reflect the arrow’s bearing.


Figure 7: Turn symbol according to travel direction (examples not exhaustive)


Grant of license:

 On behalf of Stefan Egger, IIIDre grants the purchaser of a “Tern Symbol” a time-unrestricted license to use the template on up to 5 computers per licensee belonging to a single individual, company or organization specified on the invoice. 

The licensee agrees to not modify, duplicate, reproduce, sell, transfer, license or otherwise distribute the Symbol in any form, nor make, or request others to make, modifications and/or additions unless explicitly authorised by IIIDre. 

Permitted uses: 

The use of the “Tern Symbol” on webpages and other electronically supported media is permitted but must not be made available to others for download.

Only with the explicit authorization of IIIDre the entire range of the “Tern Symbols” may be depicted resp. embedded in electronic and other documents. 

Limitation of liability: 

IIIDre warrants that the licensed “Tern Symbol” is free from defects for 90 days as of the date of acceptance of the EULA. During this 90-day period IIIDre will replace any “Tern Symbol” proven to be defect.