Option 1. Slide one card in another one by sliding the middle part of one card above the middle part of the other one while the respective side parts both slide under the other card simultaneously to the ends of the slits. The cards will lock. Option 2. Slide one slit of one card into one respective slit of another card till the end, then slide the upper part of the card into the other respectivle slit until it stops and rotate the two card in a way to align the slif of both card. The cards will lock. Note: The cards are locked when the wider middle part is fully between the side parts of the connected card. For a stronger lock, slightly bend the wider middle part outward, so it cannot slip through the slits of the other card.

Connect cards one by one in a straight line. Note: In this and other arrangements, you can pre-assemble smaller arrangements and connect them in bigger structures.

Step 1. Slide one card in another one before they are locked. Step 2. Rotate one card relatively to the other one to the desired angle or until it is stopped by the other card.

Step 1. Place one card as a center of the intersection. Step 2. Connect cards in two, three or four directions from the center card.

Step 1. Make a straight arrangement of 9 cards. You can use the concrete slab side for all or the paved road side for a road or roads going under the bridge. Step 2. Make another straight arrangement of 8 cards. Tip: When building curved card arrangements, such as bridges, get the diverging slits of the connection face outward to have a stronger lock. Step 3. Put the straight arrangment of 8 cards on the straight arrangement of 9 cards in a way that one end of the top arrangement is next to the connection of the first and second cards in the bottom arrangement. Step 4. Connect the top to the bottom arrangement by sliding the first card of the top arrangement into the connection of the first and second cards of the bottom arrangement. Step 5. Slightly slide the other end of the top arrangement inthe direction of the connection of the lasr and second last cards of the bottom arrangement. The top arrangement should bend outward forming an arch. Step 6. Connect the top to the bottom arrangement by sliding the last card of the top arrangement into the connection of the last and second last cards of the bottom arrangement. This will form the bridge. Step 7. Install supports to the bridge by adding a card to the connection of the second and third cards from the middle of the bottom arrangement on both sides and placing the free ands of the support cards on the nearest connections of the top arrangement.

Step 1. Place one card as a part of the tunnel bottom. Step 2. Take another card and make a 90 degree bend at the end of the slits using a ruler. Tip: Make the bend in a way that the concrete is facing outside, so that the tunnel will look like a concrete structure. Step 3. Repeat the bend on the opposite side of the card. Step 4. Repeat steps 2 and 3 with another card. Step 5. Connect of the bent cards to the road card from step 1. Step 6. Connect the tops of the bent cards to another card to form a tunnel section. Step 7. Repeat steps through 6 to build the required number of sections. Step 8. Connect the sections together.

Step 1. Build at least one tunnel section. Step 2. Connect a road arrangement of cards to the top card of the tunnel section. Note: Depending on the direction of the road cards, the top card of the tunnel section may require the flip side to connect with the road.

Step 1. Build at least one tunnel section. Step 2. Connect road arrangements of cards to the top card(s) of the tunnel section(s) in two or more directions.

Step 1. Make at least four cards with bends at the end of the slits using a ruler. Step 2. Connect the cards to form a channel. Step 3. Connect the channel to a road arrangement of cards or make the channel longer. Step 4. Make a straight arrangement of four cards. Step 5. Connect one end of the straight arrangement underneath the frourth card of the channel. Step 6. Connect the other end of the straight arrangement to the connection of the first and second cards of the channel, so the channel form the race track slope.

Step 1. Build 1st tunnel section with the top card facing the opposite side up. Step 2. Build 1st corner section following the tunnel instruction but connect the wall cards to form a corner. Make sure to build the corner section in a way that it can be connected to the tunnel section by cards between them and turn the road in the required direction, either right or left. Tip: same direction of the slits on the cards indicates that sections can be connected. Step 3. Connect the tunnel section and the corner section at the bottom by minimum two cards. More cards can be used to build a bigger ramp. Step 4. Connect the tunnel section and the corner section at the top. Step 5. Build 2nd corner section making sure it can be connected to the 1st corner section and keep the same turn direction. Step 6. Connect the 2nd corner section to the 1st corner section at the bottom by minimum two cards. Step 7. Connect the 2nd corner section to the 1st corner section at the top. Step 8. Build 2nd tunnel section with the bottom card facing the opposite side up. Step 9. Connect the 2nd tunnel section to the 1st tunnel section at the bottom using the same number of cards as in the connection of the corner sections. Step 10. Connect the 2nd tunnel section to the 1st tunnel section at the top. Step 11. Connect the bottom of the 2nd corner section to the top of the 2nd tunnel section. This will form a slope leading to the second level of the ramp. Step 12. Build 3rd corner section without the bottom card with the top card facing the opposite side up and to follow the same turn direction. Step 13. Connect the 3rd corner section to the top of the 1st tunnel section. Step 14. Build 4th corner section without the bottom card in a way that it can be connected to the top of the 2nd tunnel section following the same turn direction. Step 15. Connect the 3rd and the 4th corner sections at the top. Step 16. Connect the top of the 2nd corner section with the top of the 4th corner section. This will form a slope leading to the 3rd level of the ramp. Step 17. Make two cards with bends on the opposite side with the concrete facing outside. Step 18. Attach one of the cards as a supporting wall between the first and second level on the span between the 1st and 2nd corner sections. Step 19. Attach one of the cards as a supporting wall between the second and third level on the span between the 3rd and 4th corner sections. If more than two cards are used between the tunnel and corner sections, additional supporting walls may be required. Step 20. Connect cards to the required corners of the ramp as exits or continue building the ramp up to the desired number of levels.