We can’t rely on WMATA ridership forecasts.

Today, I look at forecasts for MetroRail and MetroBus for the two most recent comparable periods with available data. In the period from July 2017 through March 2018, MetroRail forecasts were above projections in four months and below in five months.

This doesn’t sound too bad until one examines the overall numbers. Metro overestimated ridership for these nine months by nearly 2.8 million. Actual ridership was 2.1% lower than expected by WMATA in its budget forecasts.

On the good news front, the rail ridership forecasts were not as off as the previous year.

In July 2016 through March 2017, WMATA overestimated rail ridership every single month, resulting in a net overestimate of 19.4 million or 13.0%. However, though WMATA projections are less wildly optimistic, notice that the skew direction remains the same.

The improvement was less strong in MetroBus ridership forecasts and the skew direction remained overly rosy. Here are the projected and actual MetroBus ridership for the most recent period.

WMATA projected more MetroBus riders every month than expected with the projections worse in the most recent months. Overall, there were nearly 4.5 million, or 5.1%, fewer riders than anticipated by the budget forecasts.

Like for MetroRail, the previous year’s MetroBus projections were abysmal.

The previous year’s projections were off by even more in every single month. WMATA overestimated MetroBus ridership by 9.3 million. Actual ridership was 9.2% lower than the forecast.

WMATA needs to reform its projections so they do not skew in favor of overestimating ridership. Indeed, if anything, it would be better to err on the conservative side since Metro’s budget relies in part on the expected collection of fares related to these projections.