Tunnel costs - comparison with surface and elevated road [numbers inside]

[Aenarion]

To help me decide how many tunnels to build, I did a little test. I started a new city, drew a two-lane road of each type of the same length and recorded the construction and upkeep costs. Results:

TYPE - CONSTRUCTION (MULTIPLE) - UPKEEP (MULTIPLE) - CON/UP RATIO
Surface - 1240 (1) - 9.92 (1) - 125
Elevated - 3280 (2.65) - 24.80 (2.5) - 132
Tunnel - 7920 (6.39) - 63.36 - (6.39) - 125

To double check I did the test again with a longer road:

TYPE - CONSTRUCTION (MULTIPLE) - UPKEEP (MULTIPLE) - CON/UP RATIO
Surface - 3040 (1) - 24.32 (1) - 125
Elevated - 8020 (2.64) - 60.80 (2.5) - 132
Tunnel - 18240 (6) - 145.92 (6) - 125

Results are almost identical, though I got slightly better value for money on a longer tunnel than a shorter one.

[Doc1979]

Thank you. This was helpful.

[Aenarion]

You're welcome.

As an aside, a tunnel costing 6 times as much as a surface route is actually pretty realistic!

[Edge]

Thanks