Nearly three-dozen groups ask Treasury to specify the act's $360B in aid can be used for transportation projects.

Despite rise in volume, construction's ranking dips to third among industries, from first in mid-April.

But industry groups say more guidance is needed for forgiveness and loans of $2 million or more.

AGC says unless Treasury clarifies new guidance, some construction firms will repay loans, lay off workers.

Pension advocacy group says local's early retirees would be hit particularly hard, facing cuts of up to 60%.

Report says infrastructure projects' capital costs total $330 billion; benefits range from $500 billion to $1 trillion.