Northern route eases supplies to US forces in Afghanistan at The International Institute For Strategic Studies. With a map, and a graph of container traffic.

Some interesting snippets:

• Moving supplies via the northern rail route costs approximately 10% of the cost of movement by air.
• NATO has also begun using the NDN. The first trial shipment of NATO cargo, consisting of 27 containers of construction materials and food supplies, departed from Riga, Latvia, in May 2010. Russia had offered transit to NATO at the Alliance’s 2008 Bucharest summit, but it was not until 2009 that NATO began negotiating transit rights with Uzbekistan and Kazakhstan, and these talks took almost a year to complete.
• [The Termez to Hairatan railway] has reached its handling capacity of 4,000 tonnes of cargo per month. Until upgrades are completed, this border crossing is likely to remain a choke point. Meanwhile, railway experts have questioned whether the existing rail route through Uzbekistan is capable of handling the amount of traffic envisioned by the US military and its allies.