The word "poll" here refers to a poll tax, or capitation tax, which in New England was assessed on the adult males of a community on an annual basis. (In Middle English, "poll" meant "head"; the term later came to mean a count of heads, whether for voting or taxation.)

In eighteenth century New England, typically about a third of taxes were collected through polls, compared to about two-thirds through property taxes (mostly land, but also livestock, money at interest, and other forms of wealth).

By the mid-19th century, the proportion of revenues raised through polls had fallen even more, by one estimate to about 16% of total revenues in Massachusetts. That being said, counties and towns sometimes levied poll taxes to underwrite roads, bridges, and ferries; the quote you include here seems to point to this purpose.

During and after the Civil War, because of the explosive growth of government expenditures, Massachusetts placed a cap on poll taxes, to ensure that the burden would not be too great on individual taxpayers - which in turn meant that by the end of the 19th century, the poll tax was an increasingly less important source of revenue; by 1874, it only accounted for 2.5% of all state funds. With the introduction of corporate taxes and later the income tax, it became even more negligible, but as late as the 1960s, citizens in New England still had to pay a small poll tax in order to vote or participate in a town meeting.

Source: Charles J. Bullock, "The Taxation of Property and Income in Massachusetts," Quarterly Journal of Economics, 31 (Nov., 1916): 1-61