Here's why:

* Density difference: Cold air is denser than warm air. This density difference creates a steeper slope on the leading edge of a cold front, allowing it to push through the warmer air more quickly.

* Wind patterns: Cold fronts are associated with stronger winds than warm fronts. These winds help to propel the cold air forward.

* Lifting mechanism: Cold fronts are more effective at lifting warm air, which can create thunderstorms and other severe weather. This rapid uplift contributes to their faster movement.

Typical speeds:

* Cold fronts: 20-30 mph, sometimes reaching speeds of 40-50 mph.

* Warm fronts: 10-15 mph, occasionally reaching speeds of 20-25 mph.

However, it's important to note that the speed of both fronts can vary depending on factors such as:

* The strength of the front: Stronger fronts typically move faster.

* The existing weather patterns: Prevailing winds and other atmospheric conditions can influence the speed of fronts.

* The terrain: Mountain ranges and other geographic features can slow down or accelerate fronts.

In summary: While there are exceptions, cold fronts generally move faster than warm fronts due to their density, wind patterns, and lifting mechanisms.