"I noticed that since I have been catching the bus, it saves gas, doesn't put as much miles on my car and plus the $100 gift card incentive," she said.

The Partnership actually administered two programs last month; the second one geared toward those who already don't drive, called Unconventional Commuters. Qualified participants of Get Downtown Unconventionally receive a $100 Visa gift card. Unconventional Commuters won various prizes throughout the month.

"We thought of this program as a way to utilize the convention as a way to rethink how they're coming into downtown Denver for their commutes," said Aylene Quale, transportation and special projects manager for the Downtown Denver Partnership.

Both programs, according Quale, were a huge success.

"One of the great benefits of this program is that participants of get downtown unconventionally and unconventional commuters tell their friends, their family and co-workers how easy it is to use alternative modes and they got other people to use them. So the effect is a domino effect of more and more people leaving their car at home," Quale said.

According to Quale, 3,000 people participated in Unconventional Commuters in August.

A total of 2,100 applied for Get Downtown Unconventionally and 1,185 registered to do the program. The registration had to be cut off more than a week early, so many people wanted in, said Quale.

More than 700 are expected to receive the $100 gift card as a reward.

For both programs, participants had to regularly log the miles they traveled to work.

Kirwin did the work and will receive the $100, but for her it was just the incentive she needed to keep that brand new car in park moving forward.

"It's just more convenient, it's saving me money, it's just smarter to me," she said.

Not everything went smoothly with the two programs.

Some commuters confused Get Downtown Unconventionally with Unconventional Commuters. They're now learning they were never eligible for the gift card and their good environmental deed will have to be its own reward.

Quale says she is flooded with e-mails about the reward, she said she was working on responding to everyone in the coming days.

Both programs were made possible with a grant from the federal government.