This is common in many crowded parts of the city and town shopping streets.I have seen mnay shopkeeper do what you are doing, I've also seen people keeping slab stone or some traffic cones even. This would be illegal.
1. You can try and have a chat with the local authorites to find a simple way around it. Instead of each shop blocking the parking slots, you can discuss in a group with the authorities so that you can have one entry point every 5 shops etc.
2.People are attracted instantly to excellent displays, artistic folds of clothes and trendy designs. Try to make you shop window or the showcase eye-catching, it will attract attention.
3.Have a pleasant manner shop assistant male/female who can encourage and invite customers to walk a few yards and then getting on the footpath. This happens a lot in our city.
4.Offer decent discounts, maintain good quality and get a group of faviourite or regular customers for your shop. Once you cutivate a pool of regular customers, these clients would not mind walking a little extra to come into your shop.
5.Have an effienceitn team led by you who will be good in converting window shoppers in actual customers who buy.
6. Ensure that the customer expereince is second to none and people will spread the word around
7.Customers like small gifts, like cloth shoppig bag, a purse or a key chain. Nothing great but help them to remember your shop.
8. Try to keep unique items that are not available in the shops around you. Offer free alterations, discount on Chudihaar stitching etc.
9. Now school season will start, try and approach schools for school uniform contracts, even if you get one or two, you will have a regular stream of customers. Try keep school bags etc too.