Inaccurate forecasts represent a major source of risk in road and toll projects because they could result in financial difficulties or even bankruptcy. This paper focuses on demand and operating cost forecasting accuracy for Norwegian toll projects by comparing the forecasted and actual levels of traffic and operating costs. The differences among the types of projects and the effects of project size, time and demand ramp-up are also examined. Our study finds that traffic forecasts for Norwegian toll projects are fairly accurate, on average. However, a majority of the investigated projects experienced overestimation, and a huge general error in the forecasts suggests that this is also a source of risk that merits greater scrutiny. Inaccuracies are common among all project types and sizes. Operating costs are frequently underestimated; on average, these costs are about 30% higher than estimated.