Restrictive procurement requirements and a lack of high-level staffing for capital projects hamstring the MBTA's ability to deliver much-needed improvements, according to a new report.

Researchers with the Pioneer Institute examined the T's spending practices over the past decade-plus and ongoing work to upgrade the Red and Orange Lines. In a Tuesday report, they concluded that, without additional hiring and changes to make awarding contracts easier, the T will struggle to reach its modernization and ridership goals.

"The MBTA will need to change the way it does business and the Legislature will have to remove unnecessary restrictions if the T is to modernize and consistently provide riders with high-quality service over time," said Pioneer Institute Research Director Greg Sullivan, one of the report's two authors.

While Sullivan and co-author Ian Ollis said the MBTA has made progress in recent years by doubling its annual spending on modernization, reliability and expansion, they warned that spending level must increase by another 60 percent to meet every goal outlined in the T's five-year plan.

Researchers also said reforms should be made to how contracts are awarded, saying the requirements the MBTA faces are unnecessarily complex and slow down projects. Gov. Charlie Baker proposed some changes in a long-term transportation bond bill he filed last month.

In the short term, the report suggested the MBTA offer more detailed updates of crucial Red and Orange Line modernization projects to boost transparency and increase spending on maintaining power systems and trains until new hardware arrives.