Critics argue that the $14 billion transportation plan approved by SANDAG allocates too much funding to highways and not enough to mass transit. The plan would extend an existing half-percent sales tax for 40 more years to fund transportation projects, but some say the funds are being diverted from their original intent of funding regional transit. A new advocacy group called San Diego Transit Riders United formed in response to the plan and what they see as growing inadequacies in transit funding. Supporters of the plan argue that it allocates funds similarly to the original 1987 plan and will support projects that benefit both roads and transit.