For regions that extend predominantly north-south, which projection is commonly used?

• A. Polyconic Projection
• B. Mercator Projection
• C. Albers Equal Area
• D. Transverse Mercator

Answer: (A)

When a region runs much longer north–south than east–west, you want a projection that minimizes distortion along that tall axis. The Transverse Mercator achieves this by rotating the standard Mercator so the projection surface is aligned with a north–south line (central meridian). This makes it conformal and maintains shapes well for a narrow vertical band, which is why it’s widely used for tall regions and for the UTM system, which maps the world in narrow north–south zones. Distortion remains smallest near the central meridian and grows as you move away from it, so choosing a central meridian close to the region’s center keeps the map accurate across the area. In contrast, Polyconic is not specifically optimized for tall north–south extents, and Mercator itself distorts more as you move away from the central area.